Many of the themes discussed in the previous chapter reappear here. Both chapters deal, at least in part, with military maps. The maps discussed here can be grouped into the same broad categories as in the preceding chapter: fortification maps, battle maps, maps of military movement, and topographic maps.
The mapping of the American Revolution is extraordinarily rich and well documented. Many Revolutionary War maps are available on the World Wide Web, particularly from the Geography and Map Division of the Library of Congress. Much of the fighting took place in New York, and consequently much of the cartography of the Revolution depicts locations in the state. Few parts of New York escaped the conflict altogether. Thus, more of the state was mapped during the Revolutionary War than during the French and Indian War. The earliest detailed maps of many parts of the New York date from the time of the American Revolution.
In comparison with French and Indian War, formal sieges of fortifications played a relatively small part in the Revolutionary War. The Revolution was much more a war of movement, with the Americans relying primarily on their ability to maneuver across vast spaces, rather than on trying to control specific positions. Because of their powerful navy, the British were often able to use water transport to move their armies, but they were handicapped by their inability to control permanently large areas of hostile territory, and by the resulting logistical problems. Because logistics and troop movement were so crucial—albeit in different ways—for both sides, detailed reconnaissance maps were relatively more important than they were in the French and Indian War.
Maps undeniably played an important part in the war efforts of both the British and the Americans. Generals like George Washington and Sir Henry Clinton were avid collectors of maps, along with other forms of military intelligence. There has been some debate about just how vital maps were in making military decisions during the Revolution. As will be seen in considering the circumstances in which specific maps were created and used, it is very difficult to pin down the exact role of maps in making particular military decisions, but they were certainly used and prized as intelligence sources.
Another subject that has been widely discussed is the extent to which the various armies had access to cartographic resources. The Americans apparently had little trouble obtaining copies of published British maps, such as Montresor’s map of the Province of New York. These important regional maps were created prior to the Revolution, although frequently not published until after 1775. The British made few efforts to restrict their circulation, and most were available to the Americans through map dealers in France or the Netherlands. In terms of wartime map production, the British army in North America had almost twice as many cartographers as the Americans, and produced nearly twice as many maps. The quality of many of the maps produced by the Americans was quite good, but they almost always lacked the polished appearance of the British maps, and the Americans did not have engraving and printing facilities comparable to those of the British. The French expeditionary force came equipped with excellent map makers, but (because of the relatively small part they played in the fighting) their output was more limited than that of the British or Americans.
It is not obvious how best to present the rich and varied array of maps created during the Revolution. They could be arranged in chronological order. They could also be grouped by geographic region (such as New York City Area, Hudson Valley, Lake Champlain corridor, Mohawk Valley, and western frontier). Instead, I have opted to arrange them by the nationality of their creators, and to subdivide them by region and type of map. Only a small percentage of the available maps can be discussed here. I have chosen examples that are either of outstanding quality, or which typify general trends in mapmaking. References presented in the footnotes should enable researchers interested in particular military events or geographic areas within New York to locate most relevant materials.
Maps of Battles and Fortifications
It is convenient to group fortification and battle maps together, since battles often took place in the vicinity of fortifications. Even though sieges of fortifications did not play as large a part in the Revolution as in the French and Indian War, both sides made and collected maps and plans of fortifications—both of their own works and those of their opponents. In the course of the American Revolution, the British produced dozens of maps of fortifications in New York. Often, they also show the surrounding region, and include information about military activities in the vicinity.
The Battle of Long Island (also known as the Battle of Brooklyn), and the battles around New York City that succeeded it, led to a particularly rich harvest of maps. There are good reasons for this. The Battle of Long Island itself was one of the most important battles of the Revolutionary War. It involved larger numbers of troops engaged on both sides than any other battle of the war. It was also a particularly interesting battle for armchair strategists, and the campaign was a success for the forces of His Majesty, which stimulated the creation and publication of celebratory maps by the British.
The stage was set for the Battle of Long Island after the evacuation of Boston in March, 1776, when the British decided to make New York the center of their operations in North America. In July of that year, they made their initial landing on Staten Island. Their forces were under the command of the Howe brothers—Major General William Howe (1729-1814) and Vice Admiral Richard Howe (1726-1799). William Howe was assisted by two other well-known Major Generals—Sir Henry Clinton (1738-1795) and Lord Charles Cornwallis (1738-1805), both of whom played important parts throughout the Revolution. Clinton and Howe detested each other, and their disagreements affected events in New York until Clinton finally succeeded Howe in 1778. By August 25, some 22,000 British and Hessian troops were disembarked near Gravesend on the southwestern corner of Long Island to face an army of approximately 19,000 under the command of General Washington.
The Battle of Long Island raises an intriguing question: were maps the key to the British victory? This question has been posed because the British outflanked the Americans by a night march through the little-known Jamaica Pass, which the Americans had left unguarded. This maneuver depended on good geographical knowledge, but it is not known to what extent that knowledge was derived from maps. Sir William Howe and other British officers would have looked at whatever maps of the area they had available, but we do not know what maps the British commanders consulted before the battle, or even whether this pass was shown on any of them. The flanking maneuver was the brainchild of Clinton, who himself had grown up on Long Island during the 1740s when his father, George, was governor of the province. It is also known that General Clinton visited this pass on a scouting expedition, and that the British troops were guided through the pass by local loyalists. It seems that the British had no lack of local geographical information, and at least one of the engineers attached to the army (George Sproule, who was soon to make a map of the battlefield) was born on Long Island. Most likely, the British decision to use this route derived from the consultation of a variety of intelligence sources, of which maps were only one, and possibly not the most important.
Be that as it may, the British produced some remarkably detailed maps of western Long Island within a few months of their victory. Shortly after the battle, a map was published “from the surveys of Major Holland” showing topography and roads in the area. The depiction of western Long Island on this map closely resembles that on Holland’s earlier map of New York and New Jersey, but it adds the morainal hills in Brooklyn, and shows the route taken by the British army in its flanking maneuver ( 7.1). A much more detailed survey of the topography of Brooklyn and the American fortifications was made by George Sproule in September, 1776. The existing copy of his striking map of this area was drawn in 1781, and may incorporate information from later British surveys.
7.1. Samuel Holland, The Seat of Action…. (1776). Library of Congress, Geography and Map Division.
Another map that shows the Battle of Long Island in considerable detail was published by J.F.W. Des Barres as part of his Atlantic Neptune ( 7.2). This remarkable map shows western Long Island with an amount of detail intermediate between the two previous maps. It nonetheless depicts the topography of the area in much greater detail than any previous published map, and probably reflects intensive surveying made in the months following the British victory. Manhattan, Staten Island, parts of Westchester County, and New Jersey are also shown in similar detail. In addition, it depicts New York Harbor and the lower Hudson River, complete with shoals and soundings. This map is a rather odd hybrid. Since the Atlantic Neptune was primarily a hydrographic atlas produced for the British Admiralty, the detailed charting of New York Harbor and the Hudson River comes as no surprise. The military information on this map is not what one would expect to find on a nautical chart. Its presence is explained by the fact that Des Barres was allowed to publish his maps for profit. Evidently, Des Barres thought that the inclusion of these military events would appeal to customers beyond the Admiralty and ship captains. It does not take much imagination to out who might have bought this enhanced version of a nautical chart: military officers, public officials, and considerable numbers of armchair strategists or people interested in contemporary affairs.
7.2. Detail of J.F.W. Des Barres A Sketch of the Operations of His Majesty’s Fleet and Army…. (1776). Library of Congress, Geography and Map Division.
The Battle of Long Island was also depicted on less elaborate maps aimed at a more general audience, which might be unwilling or unable to pay for expensive colored engravings. Many of these also included other military actions in the vicinity of New York City. Maps of this kind appeared in The Gentleman’s Magazine, and in The Universal Magazine of Knowledge and Pleasure . Several similar maps were clearly intended for sale to a wide audience. One of them was even translated into French and published in Paris. A map published by William Faden, which included a narrative of the campaign by General Howe, was apparently hawked as a broadside on the streets of London. Appearing within a few months of the battle, these maps helped to inform the literate European public about events of widespread interest. Although the analogy is not exact, it may be said that in the slower-paced eighteenth century they played a role somewhat similar to newspaper maps or to television news maps today.
Manuscript maps depicting the Battle of Long Island were made throughout the Revolution. The battle was of continuing interest to those studying the course of the war, and also to students of military tactics. British commanders continued to consult these maps in their efforts to explain events, and to justify their own ideas and actions. A case in point is this note added by Henry Clinton to the map drawn by George Sproule in 1781, based on the survey he had made in September 1776: “This map proves that there were no rebel works near the water side of Brooklyn 27 Augt. 76 & consequently S[ir] W[illiam] H[owe] was misinformed & that we might have taken possession at the close of the action and made the Island and all in it ours.” Second guessing the officers on both sides of this battle has continued to be a popular occupation, and maps illustrating the battle were also made of it in the nineteenth and twentieth centuries.
The Battle of Long Island was followed by a series of conflicts on Manhattan and in Westchester County. These included the initial British invasion of Manhattan at Kips Bay (September 15), the Battle of Harlem Heights (September 16), The Battle of White Plains (October 28), and the storming of Fort Washington (November 16). After the fall of Fort Washington, the Americans retreated to New Jersey, putting an end to this phase of the war. Most of these actions were recorded in considerable detail on maps, many of which remain unpublished. Only a few examples will be considered here to provide a sense of what is available.
It appears that no contemporary maps were published that show in detail the initial British invasion of Manhattan on September 15, although at least one detailed manuscript map exists. The location of the British landing and some subsequent operations are also shown on several overview maps, such as Des Barres’ Sketch of the Operations of His Majesty’s Fleet and Army, and on William Faden’s “broadside” map (both discussed above). However, a number of more detailed maps show the fortifications and battles on upper Manhattan. One of the best is Charles Blaskowitz’s carefully drawn plan of the British and American fortifications on upper Manhattan and Long Island near Hell Gate. Blaskowitz had been an assistant to Des Barres in surveying for the Atlantic Neptune, and we will see that he produced several other important maps for the British during the revolution.
One of the finest overview maps of the military activities on upper Manhattan was drawn by Claude Joseph Sauthier, and eventually published with some additions in 1777 by William Faden ( 7.3). With the coming of the Revolution, Sauthier had left the service of Governor Tryon, and entered into that of the British general Lord Percy, who played an important part in military activities around New York. The Geography and Map Division of the Library of Congress has digitized several states of this map, including the manuscript versions used by Faden. Sauthier also produced several more detailed maps of fortifications in this area, as well as other more general maps of military events around New York—a number of which are also available online from the Library of Congress.
7.3. Detail of Claude Joseph Sauthier, A Topographical Map of the Northn. Part of New York Island…. (1777). Library of Congress, Geography and Map Division.
A large-scale map showing troop positions at the Battle of White Plains was made by Charles Blaskowitz. This cartographer also drew a remarkably detailed map showing the location of the British landing at Throg’s Neck (or Frog’s Neck, as it was commonly called during the Revolution), and the route subsequently followed by the British troops to White Plains. This map is especially notable for its careful delineation of the topography of the area, and for the amount of information it conveys about the composition of the British troops taking part in the operation. The productive Sauthier also contributed an excellent overview map, which depicts the actions in Westchester County leading up to the Battle of White Plains, along with the military activities on upper Manhattan and in New Jersey.
The storming of Fort Washington is one of the few operations during the Revolutionary War in which the possession of a fortification map may have played an important part in a military victory. Fort Washington was the American bastion on upper Manhattan, which held up the advance of the British troops after their initial seizure of lower Manhattan in September 1776. On November 2 of that year, an American deserter named William Demont presented Lord Percy with a plan of the fort. How important the plan was to the ultimate success of the British attack later that month is uncertain, but the loss of Fort Washington was a serious blow to the American cause. A number of manuscript maps showing the assault on Fort Washington were made by those engaged on the British side (a good selection is available from the Web site of the Library of Congress). The only published maps showing the fort were more general in scope, including the maps by Sauthier mentioned in the previous paragraph.
Along with the battles around New York City in 1776, the other momentous military event of the War of Independence in New York was the Saratoga campaign of 1777. This was actually a series of interconnected battles, although the whole is sometimes referred to as “the Battle of Saratoga.” This event has been widely recognized by military historians as the turning point of the Revolution—a signal victory, which strengthened American morale and led to the French alliance. From the perspective of the history of cartography, this campaign is also interesting.
There has been a good deal of debate about the British strategy underlying the campaign. In a nutshell, the British planned to divide the colonies along the Hudson River- Lake Champlain axis, and thereby cut off New England from the southern colonies. This classic divide and conquer strategy was designed to disrupt the movement of supplies between the American armies, and to enable the British army to deal with the colonies piecemeal. The campaign was to consist of three parts: Burgoyne’s army was to move down the Lake Champlain corridor from Canada to Albany; part of Howe’s forces, under the command of Sir Henry Clinton, was to travel up the Hudson River from New York to Albany; and a third contingent under Lieutenant Colonel Barry St. Leger was to march on Albany from Lake Ontario via the Mohawk River. On paper, this strategy makes good sense. The importance of these waterways in shaping the geography and history of New York is a major theme of this book. The British correctly perceived the critical importance of these passageways, and their strategy was based on sound geographical principles.
There has been some discussion about the role of maps in determining this strategy. The decision to make the conquest of New York the centerpiece of British military activities was made in London at the highest levels—ultimately by the king and his closest advisors. King George III happened to be a map enthusiast, and he and his councilors were supplied with numerous fairly detailed maps of New York, including Sauthier’s map of the Hudson River, Montresor’s map of the Province of New York, and Brasier’s map of Lake Champlain. It is not difficult to imagine how a person looking at these maps might arrive at this strategy. However, we do not know precisely what went on in the minds of George III and his advisors, and there were other reasons why they thought this plan would work. They correctly perceived that New York City, with its all-weather port, was a strategic key to the continent. They also thought—and here they were only partially correct—that there were many loyalists in upstate New York, who would come to the aid of the British armies. And they knew from recent experience in the French and Indian War a good deal about the military importance of the waterways leading from Albany to Canada. Almost certainly, all of these considerations, in addition to maps, played a role in their decision.
Nonetheless, in this case there is a real possibility that the British were bemused and misled by their maps. A map, such as Sauthier’s depiction of the Hudson River and Lake Champlain, makes military operations in New York appear deceptively easy. Looking at such maps, it is easy to imagine armies being conveyed up the Hudson River and down Lake Champlain, and then marching short distances along roads to a rendezvous with glory in Albany. However, these maps necessarily telescope the immense distances involved; they do not show the abominable quality of the roads; and they fail to reflect the difficulties created by such obstacles as dense woods or swamps. Even today, the best of maps cannot convey the reality of marching under a hot sun in a wool uniform with a heavy pack, while being periodically soaked with rain and harassed by mosquitoes, horse flies, and other noxious insects. Neither do they show the potential for enemy militia to construct obstacles and harass troops with sniping and ambushes, nor can they depict the difficulties of maintaining fragile supply lines under such trying conditions.
This plays into the ongoing debate over the feasibility of the British strategy. A number of writers have dismissed the British effort to conquer New York and split the colonies as foolish and doomed from the beginning. Others have maintained that it might well have succeeded, and that a British victory could have put an end to the Revolution. This latter school has blamed the British defeat primarily on bad generalship, and they have much evidence to point to: the overconfidence of Burgoyne, combined with his lack of experience in fighting in the American wilderness; Howe’s astonishing decision to capture Philadelphia, rather than provide adequate support for Burgoyne in the form of a massive invasion of the Hudson Valley; the excessive caution of Sir Henry Clinton; and the overall incompetence of the alcoholic St. Leger. In my view, it is quite possible that the British, given better leadership, could have at least temporarily conquered Albany and the Hudson Valley.
It is difficult to say what the effect of such a victory might have been. Even if the British had succeeded, they would have found it extremely difficult to maintain a hold on the entire Hudson-Champlain corridor. To disrupt communications effectively between the colonies, numerous garrisons and patrols would have had to been set up, and these would have been vulnerable to being isolated and picked off by a determined enemy. On the other hand, the blow to American morale of such a victory might have been so great that the Rebels might have given up, or at least settled for a negotiated compromise. Because so much of the outcome of a war depends on morale—the willingness of both sides to continue fighting—there is, in my opinion, no telling what the long-term outcome of a hypothetical British victory in the Saratoga campaign might have been.
Doomed or not, the Saratoga campaign led to the production of a number of excellent battle maps. Burgoyne’s army was accompanied by skillful mapmakers, who produced several striking plans of the engagements around Saratoga. The British did not publish these maps with the same celebratory gusto as they did maps of the Battle of Long Island, or even the maps associated with Clinton’s foray up the Hudson, which will be described below. In striking contrast to the Battle of Long Island, only one map covering this campaign seems to have been published in Great Britain within a year of Burgoyne’s defeat. They also reprinted Brasier’s 1762 survey of Lake Champlain, and updated it to include information about the defeat of Benedict Arnold’s fleet at Valcour Bay in 1776—an event that was only distantly related to this campaign.
However, in 1780 a number of maps were engraved by Faden for Burgoyne’s account of his expedition, and these were then later republished in Faden’s Atlas of the Battles of the American Revolution. A good selection of both manuscript and printed maps of the Saratoga campaign can be found on the American Memory website of the Library of Congress. Although primarily of interest to military history buffs, several of them also provide good views of the topography of the areas around the battle sites, ( 7.4).
7.4. Anonymous, “Plan of the Position Which the Army under Lt. Genl. Burgoyne Took at Saratoga….” [177?]. Library of Congress, Geography and Map Division.
In part because of its connection with the Saratoga campaign, mention should be made of Fort Ticonderoga, which exchanged hands several times during the Revolutionary War. It was first seized by the Americans in 1775, and then lost to the British in 1777 at the beginning of Burgoyne’s invasion. The Americans regained Ticonderoga after Burgoyne’s surrender, but the British reoccupied it without much opposition in 1780-81, and it was unoccupied in the final years of the war. In spite of all this military activity, few maps were made of the fort during the Revolution. The British were well equipped with maps of Ticonderoga dating from the French and Indian War, which may partially explain their inactivity in making new maps. The only map of Fort Ticonderoga that appears to have been published in Britain during the Revolution is an adaptation of a map from the period of the French and Indian War, which was modified to show some of the American fortifications built prior to the recapture of the fort in 1777. There is also an important manuscript map by a British officer at the John Carter Brown Library, which shows the fortification shortly after Burgoyne’s successful seige. American and French cartographers also produced plans of the fort, which will be considered later in this chapter.
Two lesser military campaigns were connected with the Saratoga campaign—the attempt of the British under Barry St. Leger to march on Albany via the Mohawk River Valley, and Sir Henry Clinton’s foray up the Hudson River.
Only a single casual sketch appears to have been preserved from the British side depicting St. Leger’s expedition from Oswego to Fort Stanwix. This is fairly typical for the many small raids and campaigns fought by both sides in the Mohawk Valley and nearby areas. Generally speaking, only the larger battles were recorded by mapmakers—if only because people with cartographic skills were unlikely to be attached to small units. The Americans, as we will see, were more active in mapping this campaign.
The lower Hudson River Valley was the most heavily fortified area in the Revolutionary War. Most of these fortifications were constructed in the Hudson Highlands by the Americans, but they were all heavily contested, and the British were quite active in mapping them. Several British maps were drawn of forts Clinton and Montgomery, which guarded the chains that were supposed to prevent the British from sailing up the Hudson. Both of these fortifications were taken by the supporting expedition that was belatedly sent up the river to save Burgoyne’s floundering army. Both John Andre and Samuel Holland drew detailed manuscript maps showing the forts and their surroundings. A similar map was drawn by John Hills, and finally published by Faden in 1784. After the collapse of the British efforts to gain control of the Hudson Valley, the Americans turned the tables by capturing two fortifications that the British had built further down the river at Stony Point and Verplank Point. John Hills also drew a map of this event, entitled a Plan of the Surprise at Stoney Point…, which was also published by Faden in 1784.
In the final years of the Revolution, the most strategically important of the Hudson River forts was, of course, West Point, which guarded the critical American supply route from New England to the southern colonies. The British famously tried to obtain plans of West Point from Benedict Arnold, and John Andre’s involvement in this effort led to his capture, to his execution, and to the end of his career as a mapmaker. In spite of Andre’s misfortune, manuscript maps at the Clements Library and the Library of Congress show that the British were not completely unsuccessful at obtaining information about West Point. One of these maps, which is conveniently available on the World Wide Web, bears the title, Sketch of the Rebel Works at West Point as Taken from the Description of Them Given by a Deserter Who Came to Stoney Point, 9th June, 1779.
Finally, note should be made of the plans of fortifications constructed by the British on Long Island. Central and Eastern Long Island suffered from a particularly unpleasant situation during the Revolutionary War. Long Island was occupied by the British throughout the war, and it was an important agricultural hinterland for their army. But the British hold on it was weaker than on New York City. Much of the population sympathized with the Patriot cause, and the island was subject to raids from Connecticut. In an attempt to maintain and consolidate their hold on this area, the British built several fortifications. Only one of these (Fort Franklin on Lloyd Neck near Huntington) ranks as a major fort. The others can better be described as fortified encampments, several of which were successfully raided by the Americans. Maps have come down to us showing the British encampments at Oyster Bay, Setauket, and Mattituck, as well as the fort at Lloyd Neck. Several of them are the earliest detailed maps of these areas and their surroundings.
Maps of Military Movement
Few good examples of classic “route maps” were produced by the British Army in New York during the Revolutionary War. Such maps were made for the campaigns in New Jersey and the southern states, but are largely lacking in New York because the British relied on water transport in New York for most of their long-distance movements. Some of the overview maps published of the Saratoga Campaign, described above, might be considered to be route maps. Probably the best example a route map created by the British showing events in New York is Sauthier’s map summarizing the campaigns in Westchester County and New Jersey following the seizure of Manhattan. This work, which could also be described as a type of battle map, is cited in note 25 above ( 7.5). Like many route maps, it has a great deal of white space, and mostly shows what could be mapped from the line of march. In addition, British military officers produced rather sketchy maps of roads on Long Island and in Westchester County, but these can better be described as reconnaissance maps. Better examples of route maps in New York were produced by the American and French armies.
7.5. Claude Joseph Sauthier, A Plan of the Operations of the King’s army…. (1777). Library of Congress, Geography and Map Division.
The British produced quite a few Reconnaissance maps. These were characteristically produced for areas that the British held loosely or contested periodically. Consequently, they often provide information about places that are not covered in detailed battle maps or military topographic maps. During the Revolutionary War, British reconnaissance maps were most often made for eastern Long Island, Westchester County, and other parts of the lower Hudson Valley. Sometimes they provide information about roads and buildings that cannot be found in any other source.
A number of sketch maps of eastern Long Island fit into this category. One was produced by a Hessian officer, and bears the title “Plan of Long Island in New York Governement Nort [sic] America.” It appears to be a tracing of a printed map, but it contains some additional information. Thus, a tavern is shown in the middle of the Pine Barrens of central Suffolk County. This was obviously a matter of considerable strategic importance to soldiers crossing this sparsely inhabited area, but it cannot be found on any other map.
Several of these sketch maps covering areas on eastern Long Island come from the pen of John Andre, the famous British army officer who was captured and hanged for his role in Benedict Arnold’s treasonous scheme to betray West Point. The most interesting of Andre’s maps is a sketch of the area around “Cannoe Place” (where the modern Shinnecock Canal is located in Southampton). This is the only British Revolutionary War map I have been able to locate that shows in detail any part of Long Island’s South Fork, except for its tip. Andre notes on this map a “commanding height” for the emplacement of guns (Sugerloaf Hill), the location of a “proposed redout,” and a “small Indian settlement” of the Shinnecock tribe. As Sir Henry Clinton’s adjutant general and aide de camp, Andre was also responsible for maintaining the British Headquarters maps and papers, which are now at the Clements Library at the University of Michigan.
This collection of British headquarters maps at the Clements Library also includes numerous reconnaissance maps for Westchester County and other Hudson Valley areas. A few similar maps are at the Library of Congress, and can be viewed online. These maps run all the way from hastily sketched road maps, through sketches of military topography, to elaborately detailed maps that show individual houses. Some of them approach in quality the topographic surveys that are described in the following section. Several of these maps show houses and even give the names of individual homeowners. An example of one of these more elaborate surveys is shown in 7.6 below. 
7.6. Andrew Skinner, “A Map Containing Part of the Provinces of New York and New Jersey….” (1781). Library of Congress, Geography and Map Division.
Topographic Maps and Nautical Charts
Elaborate topographic maps covering large areas are not usually made by military cartographers during time of war. Prior to the twentieth century, detailed surveying could not be carried out under wartime conditions, and the production of these maps was so time consuming that military map makers were usually called upon to spend their time on more urgent tasks. But the American Revolution provides a partial exception to this generalization. After the British seized New York City in 1776, they produced numerous military surveys of Manhattan and its environs. The British occupation of this area made it safe for the surveyors to do their work, and since they were confined to the vicinity of New York for long periods (especially after Yorktown), they had time on their hands for detailed mapping. Such work was valuable, both for planning the defense of the city against possible attacks by the American and French forces, and also for such mundane purposes as gathering military supplies.
This group of military maps includes the charts of the New York City area published in Des Barres’ Atlantic Neptune. As noted in the previous chapter, the extensive and detailed coastal surveying embodied in the Atlantic Neptune had to be suspended at the outbreak of the Revolution, just as it was reaching New York. However, the Neptune—all of which was published sheet-by-sheet after 1775—includes several charts covering the New York area. Most of these charts include detailed topographic mapping of areas well inland from the coast, as well as such standard navigational information as soundings and indications of shoals and rocks.
One can only guess how much, if any, of the work on these charts was done prior to the Revolution. Most of the surveying was done by Samuel Holland and other military surveyors after the British occupied New York City in 1776. Several of them were published in multiple editions during the Revolution, which sometimes included additions providing more detail or bringing them up to date. The nautical information on them was of particular importance to the British military, since naval activities in the vicinity of New York were critical for the entire British war effort.
The Des Barres chart showing New York Harbor and the course of the Hudson River as far as Stony Point has already been mentioned in connection with the Battle of Long Island. While this chart showed most of western Long Island and Westchester County, and included military information (evidently to increase sales), it also was much more accurate and detailed than all previous nautical charts of New York Harbor. This chart, published in 1777, does not include a list its sources, which may have included both surveys conducted prior to the outbreak of the Revolution and surveys made during or shortly after the British invasion. A similar chart was published as part of the Atlantic Neptune in 1779, although it is restricted to the entrance of New York Harbor and includes somewhat more detailed information for pilots. This chart bears a note stating that it was “composed from surveys and observations of Lieutenants John Knight, John Hunter of the Navy & others.” Hunter, at least, was on board Howe’s flagship during the invasion of New York, which hints that much of the chart was probably based on surveys done by the British navy in 1776 or shortly thereafter. John Knight was an assistant of Des Barres, who later became and admiral.
The Atlantic Neptune also included a chart of the Hudson River in the vicinity of Forts Montgomery and Clinton. It was published in 1779, is based on a manuscript map made by Samuel Holland in 1777, and is another example of Des Barres attempting to use a British military victory to boost sales. This chart also extends somewhat the coverage of the Hudson River in The Atlantic Neptune.
Several sheets of The Atlantic Neptune cover harbors and coastal areas of Westchester County and parts of Long Island. Long Island Sound was critical to British efforts both to secure the valuable agricultural areas on Long Island, as well as to carry out military operations against coastal Connecticut and Rhode Island. One of these charts shows the East River, Hell Gate, and the western portion of Long Island Sound. This medium-scale chart includes extensive soundings, but little information about topography beyond the coastline. Another chart gives more detailed coverage of Oyster Bay, Huntington Harbor, and Hell Gate, including inland areas. A third chart shows the eastern entrance of Long Island Sound, including parts of the north and south forks of Long Island, along with Fishers Island and much of Peconic Bay. This area was particularly important for British efforts towards the end of the Revolution to monitor and disrupt the activities of the French and Americans in the Rhode Island area. The second (1781) edition of this chart is an important source of information about features on the land in these areas.
The coast of New York is not shown in its entirety on any of the above maps. Two small-scale charts in The Atlantic Neptune do between them show all of coastal New York, but they are not especially accurate, even considering their small scale and the time when they were published. This reflects the lack of comprehensive surveys from New York to the south prior to the Revolution, and the fact that surveys made during the Revolution covered only limited areas of high military value. This also shows that The Atlantic Neptune was in part a commercial production. Although most of the charts in that publication were of remarkably high quality for the time, Des Barres was not above publishing inferior charts when he had no alternative available.
Finally, we come to the remarkable large-scale topographic maps of the area around New York City produced by British military surveyors in the years between 1776 and 1783. None of these were published in the eighteenth century, and they are relatively little known. One of the earliest of this group is a survey of Staten Island drawn by Sauthier in 1776 “by Order of His Excellency General Howe, Commander in Chief of His Majesty’s forces in North America.” Staten Island was the site of the initial British landing preceding the Battle of Long Island, and Howe evidently recognized the value of having a detailed map of the area. It is a very large-scale manuscript map (1 inch to 2,112 feet), which shows such details as individual fields and buildings.
The British also made numerous maps of Manhattan during the period of their occupation. Their makers included such prominent cartographers as Sauthier and Samuel Holland. Augustyn and Cohen have remarked: “As a result of the presence of these surveyors and engineers in the city through the war, New York, which was one of the most poorly mapped American cities before the war, became by its end the most thoroughly mapped urban area of the United States.” The most impressive of these maps is an anonymous production usually known the “British Headquarters Map,” which shows the entire island of Manhattan at the very large scale of 1:9748 (6.5 miles to an inch). Copies of this map are available at large research libraries in the form of a 22 page facsimile published in 1900 by B.F. Stevens. In addition to the expected roads, fortifications, and houses, this map shows the topography of Manhattan in minute detail. This makes it an invaluable resource to researchers who want to know what Manhattan looked like before the extensive infilling and construction that have completely transformed the surface of the island.
A comparable level of detail is available on many manuscript maps produced during the final years of the Revolution covering the boroughs of Brooklyn, Queens, and Richmond (Staten Island), as well as for parts of Westchester County. Many of these can be found in the Clinton Collection at the Clements Library; others are scattered among various archives in the United States and Britain. One example of these manuscript maps has been put online by the Library of Congress. Although not as detailed as some, it gives a good idea of their general appearance ( 7.7).
7.7. Detail of anonymous “Plan of New York and Staten Islands with Part of Long Island, Survey’d in the Years 1781, & 82” (manuscript map, 1782?). Library of Congress.
Especially after Yorktown, the British army was almost completely confined to the area around New York City, and the military engineers had time on their hands. Although mapping provided a kind of relief work for under-employed military surveyors, the existence of these maps also owes much to the cartographic interests of Sir Henry Clinton, the British commander in New York after Howe’s resignation. Many of these maps can be found in Clinton collection at the Clements Library, and several of them bear handwritten annotations by Clinton himself. Often they are dedicated to Clinton or expressly “surveyed by order of His Excellency General Sir Henry Clinton K.B. Commander in Chief of His Majesty’s Forces &c. &c.” Brooklyn received particularly detailed treatment. For example, Andrew Skinner’s “Map of the Environs of Brooklyn” is at a scale of 1:7920, which is even more detailed than the Headquarters map of Manhattan. Brooklyn continued to be of depicted in detail in 1781 and 1782 partially because of continuing interest in the Battle of Long Island of 1776. Thus, among the maps produced at this time is a detailed depiction by George Taylor of the Jamaica Pass at a scale of 1:6034. Clinton annotated several of these maps, for he seems to have been somewhat obsessed with refighting the Battle of Long Island. It is not difficult to understand why: Clinton played an important role in that battle, having managed with great difficulty to persuade the reluctant Howe to engage in the successful flanking maneuver through the Jamaica Pass. Some of his annotations reveal that Clinton bitterly blamed Howe for failing to capture Washington’s army, which he thought might have ended the Revolution.
American maps of the Revolution generally lack the polish of the detailed topographic maps produced by the British military engineers, and the Americans did not have the facilities to engrave and publish elaborate maps. The total output of manuscript maps by the Americans was also somewhat lower than that of the British. Nonetheless, the Americans produced a respectable number of maps, and overall their quality (in terms of geographic accuracy) is comparable to those of the British. Since the Americans and the British controlled different parts of New York, one can often find the best and most detailed coverage of certain areas on maps made by the Patriot side. In addition, it is always interesting to see maps of contested fortifications or battles made by both sides. In some cases, the only existing maps of certain events come from the Americans. A comprehensive list of almost all of these maps is contained in Guthorn’s American Maps and Map Makers of the Revolution. Here only the highlights and general trends will be presented.
Maps and Plans of Fortifications
As one would expect, the Americans produced numerous maps and plans showing the fortifications they constructed, attacked, or spied upon. These include maps of the fortifications constructed on Long Island and Manhattan prior to the British invasion.
The strategic importance of the Hudson River Valley was recognized at the very beginning of the Revolutionary War by the Americans. As early as 1775, Bernard Romans began building fortifications in the vicinity of West Point. Romans had considerable experience as a map maker, having served as an assistant to Gerhard de Brahm, who was Samuel Holland’s counterpart for the southern colonies. Romans was one of the very few British military engineers who took the American side during the Revolution. He is best known for a map of Connecticut that includes Long Island, but his productions also include two maps of the Hudson River near the Hudson Highlands, and several plans of his proposed fortifications. The most detailed plan of Fort Montgomery appears to be the one drawn by Romans’ successor, William Smith. Smith was in turn succeeded by Thomas Machin, who drew a remarkably detailed pen-and-ink map of the Hudson Highlands. Machin’s map is dedicated to “George Clinton Esq. Governor of the State of New York” (who should not be confused with the numerous other Clintons who played important roles in New York State history, and especially not with the British General Sir Henry Clinton). Machin enjoyed turning the tables on the British by noting on his map that certain structures were “burnt by the British rebels,” and designating as the “rebel route” the path the British took when they attacked Stony Point. After the construction of West Point, several maps were produced by French and American cartographers showing that fortification.
Another fortification that played a major part in the Revolutionary War was Ticonderoga, which (as described above) exchanged hands several times. In 1775 it was seized by the Americans, who put its guns to use at the siege of Boston. Its fall in 1777 to the British under Burgoyne was an embarrassing setback for the Patriots: the British forced them to evacute Ticonderoga by dragging guns to the top of nearby Sugar Hill, which overlooked the fort, and which the Americans regarded as “unclimbable.” As has been mentioned, the British appear not to have created any maps depicting these engagements. On the other hand, the Americans made several maps showing Ticonderoga and its immediate surroundings. One of these was by John Trumbull (1756-1843), who later became famous as a painter of portraits and patriotic subjects. He visited the fort and drew a map entitled ” Ticonderoga & its Dependencies, August 1776,” which showed Sugar Hill as “unclimbable.” Quite a good map of Ticonderoga at the time of the British siege in 1777 was engraved and published as part of the transcript of the court martial of the American General Arthur St. Clair, who was acquitted of charges arising from the American defeat.
Several maps produced by the Americans are the only visual records of some of the smaller Revolutionary War fortifications. This seems to be the case with Fort Stanwix, which the Americans rebuilt and named Fort Schuyler. The unexpected strength of this fortification was a major reason for the defeat of the St. Leger expedition. The man responsible for rebuilding the fort was Francois de Fleury, a French engineer who volunteered to work with the American army. After the siege, he drew a careful “sketch of Fort Skuyler,” which shows both the topography and military actions near the fort.
American spies were active in producing maps of British fortifications on Long Island and elsewhere in the New York City area. Guthorn in American Maps lists nine such maps. Benjamin Tallmadge was probably responsible for maps of two small British forts on Long Island— Fort Slongo and Fort St. George, both of which were successfully raided by the Americans. No other maps of these forts seem to exist. One of his maps of Fort St. George, which is at the same time both crude and accurate, has considerable artistic appeal.
Although some of the fortification maps discussed above show the positions of opposing troops, classic “battle maps” were not an American specialty. In the case of the battles around New York City in 1776, the contrast between the British and American output is dramatic. On the American side, only three small and crude woodcut maps were published, all of which bore the same title and appeared in almanacs published in New England. Although this campaign was not one for Revolutionaries to celebrate, the lack of more extensive American coverage in this case also reflects the lack of skilled surveyors in the Continental Army at that time, and the primitive state of American map publishing.
There is equally little American coverage of the Saratoga campaign, even though it was possibly their most important victory of the war. The only published American map of any part of this campaign is the one of the area around Fort Ticonderoga (mentioned above), which was prepared for St. Clair’s court martial. In addition to fortifications, this map shows enough military activities for it also to be described as a battle map.
Maps of Military Movement
Although American cartographers produced relatively little in the way of fortification or battle maps, they shined in the drafting of route maps. In fact, the overwhelming majority of maps produced by Washington’s headquarters were road maps. Most of these were drawn by Robert Erskine (1735-1780), who was appointed Geographer and Surveyor-General to the American Army in 1777. Others were also involved in the production of these maps, especially Erskine’s successor, Simeon De Witt (1756-1834), who later became Surveyor General of New York, and will play a starring role in the next chapter. Most of these maps are in the Erskine-De Witt collection at the New York Historical Society. Guthorn lists some 125 maps by Erskine and De Witt in this collection. Most are road maps, and many consist of multiple sheets.
This emphasis on road maps clearly reflects the situation and needs of Washington’s army. With his limited forces, Washington had to be nimble and shift his troops around to meet threats from different directions. He also had to avoid entrapment by a superior British force, and to obtain supplies wherever he could find them. Since Britain controlled the seas, land transportation was his only option. All of this explains the need for good road maps. Because of New York’s central location between the northern and southern colonies, Washington frequently had his headquarters in the Hudson Valley. For this reason, a high percentage of Erskine’s maps show roads in New York, particularly in the strategic corridor just north of the Hudson Highlands linking Connecticut with New Jersey and Pennsylvania.
Most of Erskine’s road maps are unpretentious but accurate. We have a good idea of how he went about making them, since he described his procedures in considerable detail to Washington. His preferred method was to measure the roads with chains, and to use a surveyor’s compass and a plane table to fix the location of nearby landmarks. One suspects that when pressed he might have measured distances by pacing. Most of his maps were made at a standard scale of one mile to an inch. Erskine knew how to use more sophisticated instruments, such as theodolites, for measuring vertical elevations and for making more accurate estimates of the locations of distant objects, but it is uncertain how often he actually used them. One of his maps is proudly labeled “Width of N.R. [North River or Hudson River] at Closter A and B. at Dobbs Ferry measured with a Theodolite.” Another of his exercises is an unfinished spherical projection of an area around the New York – New Jersey border. Some of De Witt’s maps from this period are explicitly made on a conic projection, which also seems to have been used by Erskine for some of his maps of larger areas. Thus, Erskine’s knowledge of cartographic techniques was up-to-date and sophisticated for its time, but for practical reasons he was rarely in a position to do very elaborate mapping. In all of these respects, his position was similar to that of British military surveyors like Samuel Holland.
Erskine and De Witt produced several topographic maps of larger geographic regions, which bear comparison to the productions of the British military engineers. They were made at a variety of scales throughout the period from 1778 to 1783. One of the reasons why Erskine made a point of using a plane table to ascertain the position of landmarks visible from roads is that he could use these positions to link together his road surveys across broad areas. The resulting maps reveal their origin as collations of road maps very clearly. Roads appear very prominently, along with houses along the roads, streams, hills, and other conspicuous landmarks. There is, however, a good deal of white space on these maps in places away from the roads—indicating that little surveying was done in such areas. Many of these maps appear to be at least as accurate as the maps of the region around New York done by the British military surveyors during the Revolution, but they lack the polished appearance and the amount of topographic detail that appears on the British maps.
One of the best examples of Erskine’s work is a map of Orange and Rockland Counties, which is available on the Library of Congress Web site ( 7.8). This regional map is typical of Erskine’s work. It was clearly built around a framework of road surveys: the roads are carefully drawn in, with nearby features including fortifications and individual houses shown in detail. The broader topography is sketched in a more generalized fashion.
7.12 Detail of Robert Erskine, “ [Map of Orange and Rockland counties area of New York] (manuscript map, ). Library of Congress, Geography and Map Division.
Erskine was involved not only in making his own maps, but in directing and coordinating the activities of others. In this connection, particular mention should be made of the mapping of the Clinton-Sullivan campaign against the Iroquois. This expedition, which took place in 1779, was a destructive retaliatory raid against the Indians. It was intended, at least in part, to put an end to the bloody raids conducted by British Loyalists and their Iroquois allies in the Mohawk Valley and elsewhere. The Clinton-Sullivan expedition succeeded in burning 40 villages and destroying vast amounts of crops in the Iroquois heartland, although it resulted in few deaths on either side. Predictably, it did not have much effect in limiting raids on American frontier settlements, although it created a massive refugee problem for the Iroquois and the British at Fort Niagara. In the long run, the American victory in the Revolution destroyed the political and military position of the Iroquois, and the expedition helped make the Americans more aware of the desirability for farming and settlement of the lands around the Finger Lakes. This set the stage for the rapid westward expansion of New York in the decades following the Revolution.
Whatever else may be said about the campaign, it was well mapped, which in itself was unusual for Revolutionary War activities in western New York. The surveyor of this expedition was Benjamin Lodge, whose first map made for the army was criticized by Erskine as “a most abominably lazy slovenly performance.” Lodge evidently took Erskine’s criticisms to heart, for his subsequent maps are carefully executed route maps very similar to Erskine’s own. Lodge sent his maps back to Washington’s headquarters, and they can now be found in the Erskine-De Witt collection at the New York Historical Society. Cartographically speaking, the most spectacular result of the Sullivan-Clinton expedition was an anonymous map based on Lodge’s surveys, which was compiled at Washington’s headquarters. This is a carefully finished, colored map that closely resembles many of the maps produced for the British headquarters. It shows Indian villages, the movements and encampments of the American forces, several of the Finger Lakes, and some topography. The large amount of white space on the map reveals the extent to which it was made from surveys taken along the route of the armies, as they proceeded along the Susquehanna River, into the Finger Lakes area, and thence to the Genesee River (7.9).
7.9. Detail of Anonymous, “ Map of Gen. Sullivan’s March from Easton to the Senaca & Cayuga Countries” (manuscript map, ). Library of Congress, Geography and Map Division .
The French made a variety of contributions to the mapping of New York during the Revolution. Their army played a relatively minor role in the campaigns in New York, although they did produce some maps that are directly associated with their military activities in this area. In addition, French map publishers reprinted a number of British or American maps that depicted the theatre of war in New York, and some French engineers, who served as volunteers in the American army, also drew maps.
French map publishers were remarkably active in republishing maps of British North America from about 1750 through the period of the American Revolution. The production of French maps of North America speeded up noticeably after 1776. Thus, in 1777, French editions appeared of the important regional maps by Mitchell and Jeffreys, and also of Montresor’s maps of the Province of New York and of New York City. Many of these maps were published in Paris by George-Louis Le Rouge, who specialized in American materials. Some of the maps published in France more directly reflected events of the Revolutionary War. In 1776 Le Rouge republished a British map showing the Battle of Long Island. In 1778, the Depot de Marine published a map of New York Harbor based largely on the work of Des Barres. And in 1777 Brion de la Tour created a map of the North American “theatre of war” showing the events of the Saratoga campaign.
These French editions of British maps are important for two reasons. First, they are indications of the intense French interest in the American Revolution, which led to their intervention at the end of 1777. And they were also significant sources of cartographic information for both the French and the Continental armies in America.
It is debatable whether the maps made by French volunteers working for the Continental Army should be counted as French or American productions. Guthorn treats them as American in his American Maps. To further complicate matters, the French language was frequently used during the Revolution by non-French European cartographers, particularly by Germans. Thus, there are a number of maps with French titles in the Clinton collection and elsewhere made by Hessian officers working for the British. One of the most remarkable of these was made by Charles de Gironcourt—one of a number of Hessian officers employed by the British who were born in France or had French ancestors. A few German officers on the American side also wrote in French. And, if this is not confusing enough, it has been estimated that as much as one-third of Rochambeau’s army was made up of native speakers of German. Thus, one needs to be cautious in ascribing anonymous maps in French to French cartographers.
There is, nonetheless, indisputably a significant group of maps made by French cartographers serving in the American army. The map of Fort Stanwix by Francois de Fleury, mentioned above, belongs to this group. A similar situation arises with Michel Capitaine du Chesnoy, an aide to Lafayette. Guthorn lists some 19 maps that he made during the Revolution, although only one of them covers a part of New York. In addition, Chesnoy made a map of American and British positions at Ticonderoga in 1777. Maps of New York can also be found among the works of two other French military engineers working for the Americans: Etienne de Rochefontaine and Jean de Villefranche. Rochefontaine’s maps include a detailed reconnaissance map of the British defenses around New York prepared for Washington and Lafayette 1n 1781. Villefranche drew detailed maps of West Point and the Hudson Highlands.
The only French army on American soil during the Revolutionary War was headed by Jean-Baptiste-Donatien de Vimeur, comte de Rochambeau (1725-1807). The Rochambeau Campaign of 1780-82 is well documented, and many of Rochambeau’s maps have been made available on the Web by the Library of Congress, including his personal atlas. What emerges from this documentation is the extraordinarily systematic and extensive use of maps by Rochambeau and the French army. The Rochambeau collection includes a wide range of French, English, and American published maps of North America. The French were also meticulous in documenting their military activities. Detailed route maps were prepared for the march of the French army from Rhode Island to Yorktown. The Rochambeau Atlas at the Library of Congress includes plans of virtually every camp the French army set up during this march, including some in New York.
Only a small percentage of these maps depict places in New York. Prior to the Yorktown campaign, Washington and Rochambeau considered attacking the British in New York City. A good deal of reconnoitering was done of the British positions in the vicinity of New York. These activities led to the production of a number of maps of the New York area, ranging from geographical overview maps to highly detailed plans of the British fortifications at Throg’s Neck and on northern Manhattan. This reconnaissance work also led to the production of several maps of the Huntington area on Long Island, including the British fort on Lloyd Neck. These maps testify to effective intelligence work, and doubtless reflect the efforts of both French and American spies and mapmakers. Franco-American collaboration did not always work perfectly. One anonymous map of the Lloyd Neck area carries the plaintive annotation (in French): “Bay to which the American pilots should have led the ships.”
One result of all of this intelligence work was that Rochambeau succeeded in convincing Washington to drop his plan to attack the strong and well fortified British position at New York City, and to undertake the Yorktown campaign instead. Washington did not completely abandon his plan to attack New York until August, 1781, when the French and American armies combined near Dobbs Ferry to reconnoiter the northern defenses of Manhattan. This effort is reflected in a particularly elegant map of the lower Hudson Valley entitled Position du camp de l’armée combinée a Philipsburg du 6 juillet au 19 aoust .
The march in late August from Newport, Rhode Island, to Yorktown took Rochambeau’s army across the Hudson River at Stony Point and along the west bank of the river before crossing New Jersey to Philadelphia. After the victory at Yorktown, the French army turned around and marched back to Boston. Maps of the French encampments on the return march can be found in the Rochambeau atlas and elsewhere. Particularly noteworthy are the maps showing the French and American encampments near Peekskill.( 7.10)
7.10. Anonymous, ” Position des Armées amériquaine et françoise….” (manuscript map, ). Library of Congress, Geography and Map Division.
The armies that fought the Revolutionary War built upon the maps of New York that had been made between 1750 and 1775. They added to this pre-existing cartographic knowledge by creating detailed regional and local maps, particularly of the area around New York City and of the Hudson Valley region. Cartography being to some extent a cumulative activity, this provided a foundation for much of the mapping of New York in the decades following independence.