French Engineers at Butts Hill Fort
Results of Research in the Archives du Génie, Service Historique de la Defense (SHD) and in the Archives Nationales de France (ANF) for Manuscripts and Maps related to French Engineers at Butts Hill Fort in Portsmouth, Rhode Island
Format: Numérisation
Usage: Diffusion publique pour publication, exposition…
Cote: GR 1 VN 7
Identification précise des documents: Plan de la Position de l’Armée Françoise au tour de Newport et du Mouillage de L’Escadre dans la Rade de cette Ville.
Table of Contents
This report is part of the on-going project of research into the history of Butts Hill Fort.
In this report archival research was conducted in the Archives du Génie in the Service Historique de la Defense in Vincennes and in the Archives Nationales de France in Paris.
The three most important results of this research were
These reports of the late summer of 1780 provide the best evidence of the condition of Butts Hill Fort at the point of arrival of French engineers prior to the commencement of improvements carried out by soldiers of Rochambeau’s Expeditionary Corps under the supervision of French engineers.
The primary sources in this report have not been published before. They confirm Butts Hill Fort’s strategic role as a communications and reinforcement node between Rhode Island and the mainland. More importantly, however, the analyses of the fort as French engineers found it in the summer of 1780 help to explain when, why and by whom alterations in the original lay-out were made.
As part of research into the role of Rochambeau’s French engineers in the improvements of Butts Hill Fort in Portsmouth, Rhode Island in 1780/81, maps and manuscripts in the Archives du Génie, the French Engineer Archives in the SHD, and the ANF in Paris were investigated.
This research had three goals:
1) identify maps and descriptions of Butts Hill Fort describing the defensive works as French engineers in the comte de Rochambeau’s army encountered them upon arrival in Rhode Island in July 1780,
2) document subsequent modifications made prior to the June 1781 departure of the majority of Rochambeau’s infantry from Rhode Island. Rochambeau left a detachment of almost 600 men infantry and 130 artillery troops in Newport to protect the fleet. All but 100 troops deployed to Providence sailed with the fleet to Virginia on 23 August 1781.
Rochambeau also asked Rhode Island and Massachusetts Bay to each send 500 men to Newport to help protect the fleet. Being stationed at Newport, the Rhode Islanders were never at Butts Hill. Col. Turner’s Regiment of Massachusetts militia were stationed at the fort in July 1781 but there is very little documentation for their activities during the period from July to August. Looking into the activities of Turner’s men is outside the scope of this report and awaits further research.
3) transcribe and translate these sources in English to support a better understand the construction of Butts Hill Fort.
All transcriptions and translations of these primary sources are available here:
This link takes you to all transcriptions and translations. There are also separate links further down in the text where these manuscripts are described.
In preparation of this research a 2024 report describing activities of French engineers based on orders in Rochambeau’s livre d’ordres (Orderly Book) was produced. The report includes a brief history of the French Corps of Engineers up to the French Revolution, biographical data of engineers in Rochambeau’s army, and a list of manuscripts and maps kept and/or drawn by the engineer officers in Rochambeau’s army compiled prior to this latest research in France.
This preparatory report « Rochambeau’s Engineers at Butts Hill Fort, July 1780-June 1781. Research Report prepared for The Battle of Rhode Island Association (2024),” is available here.
A video presentation introducing the report can be accessed here.
The list of manuscripts and maps listed in the 2024 report that formed the basis for subsequent on-site research in France was compiled based on data in
Howard C. Rice Jr. and Anne S. K. Brown, The American Campaigns of Rochambeau’s Army 1780, 1781, 1782, 1782. 2 vols. (Princeton and Providence : Brown University Press, 1972), vol. 2, pp. 109-204.
Nicole Salat and Emmanuel Pénicaut, Le dépôt des fortifications et ses archives, 1660-1940 : Archives du génie, répertoire numérique détaillé de la sous-série 1V du Service historique de la Défense. (Vincennes : Service historique de la défense, Archives et culture, 2011), pp. 326-369.
Section “Maps and Views” in vol. 2 of Rice and Brown, American Campaigns, pp. 109-204, page 117 reads:
“The Royal Corps of Engineers has contributed maps by Crublier d’Opterre and others (Nos. 5, 6, 43, 44, 45, 102, 103, 160, 161). Most of the (p. 118; all page numbers refer to vol. 2 of Rice and Brown, American Campaigns) other maps come from the papers of Louis Alexandre Berthier”.
None of the maps reproduced in Rice and Brown, American Campaigns, are located in the Archives du Génie.
Map 5 (p. 125, Newport), Map 44 (p. 138, Reconnaissance New York), Map 102 (p. 167, Portsmouth, VA), Map 103 (page 168, Portsmouth, VA), Map 160 (p. 194, Portsmouth, NH), Map 161 (p. 195, Portsmouth, NH) were drawn by Crublier d’Opterre.
The maps listed as drawn by Crublier d’Opterre are owned by the Beinecke Rare Book and Manuscript Library at Yale University. The library website lists the collection as Henri Crublier d’Opterre journal and maps, [1776]-1783, Call No. GEN MSS 499.
The eight maps in the Crublier d’Opterre collection can be accessed here.
The manuscript journal is dated 30 October 1781. It is written in two columns, one marked as “Texte” covering the siege of Yorktown with references to the map “Carte des Environs d’york,” and one column identified as “Notes” with general observations on the siege. The map can be accessed here.
Map 6 (p. 126, Newport), Map 43 (p. 136, Reconnaissance New York) and Map 45 (p. 138, Reconnaissance New York) are all in the Library of Congress.
A note to Map 40, “Position of the American and French Army at Philipsburg” on pp. 135/36 reads that a similar map is in Bibliothèque du Génie, MS A 224, ‘Atlas de la Guerre d’Amérique,’ fol. 79.”
A note to Map 100, “Profile of Yorktown Fortifications” on p. 166 reads: “A similar map, including the vignette, is in the Bibliothèque du Génie, Paris, MS A 224, ‘Atlas de la Guerre d’Amérique,’ fol. 79.”
A note to Map 162, “General Map of the Camps and Marches of the French Army” on p. 197 indicates that several versions of this map exist, one of them in “Bibliothèque du Génie, Paris, MS A 224, ‘Atlas de la Guerre d’Amérique,’ fol. 67.”
Atlas de la Guerre d’Amérique is a collection of printed maps, e.g. Fadden, Montresor, Blaskovich &c, but also contains many hand-drawn maps of a wide variety of sizes. They cover the whole war both geographically as well as chronologically. The maps are bound in a large atlas measuring approx. 4 feet by 3 feet. Use, including reproduction of any of these maps, or details thereof, is free, but you need to apply for permission – in writing – and SHD requests a copy of any publication.
A note to Map 43, “Reconnaissance of the Works on the Northern Part of the Island of New York” on pp. 137/38 of Rice and Brown, American Campaigns, indicates that several versions of the map exist, one of them, “accompanying an ‘Analyse d’un mémoire sur l’attaque de l’Isle de New York …’ in the Archives du Génie, 14-§-1 (Place Etrangères: New York).“
A note to Map 87, “Plan of the Siege of York” on p. 158 mentions maps by Querenet de la Combe, in “Archives du Genie 14, 15, « Sièges: York aux États-Unis »”
On the same page at the end of first paragraph, Rice and Brown, American Campaigns, write: “A similar map [of the siege of Yorktown] is preserved with an anonymous 17-page manuscript text entitled “Siège d’York defendu par le Lord Corno Wallis …” in the Archives du Génie, 15 (Sièges: York aux Etats-Unis”), pièce 2.
This map “may be attributed to the Berthier brothers.” The entry on the chevalier d’Ancteville on page 287 of vol. 1 of Rice and Brown, American Campaigns, mentions “an incomplete copy of the d’Ancteville journal (but not identified a such) in the Archives du Génie, article 15-1-7, pièce 19.”
NOTE: The bibliographic data MS A 224, ‘Atlas de la Guerre d’Amérique’ used in Rice and Brown, American Campaigns, is still in use by the Archives du Génie in SHD, however, in preparation for a research visit in Vincennes a researcher needs to confirm and/or identify all call numbers in the finding aid before he/she can order them via the SHD website.
Hereafter instead of the bibliographic data in Rice and Brown, American Campaigns, using the old call numbers, the current call numbers listed in Salat and Pénicaut, Le dépôt des fortifications, will be used in the presentation of maps and manuscripts. These call numbers must be used to order files.
The call numbers “Archives du Génie, 14- x – x” used in Rice and Brown, American Campaigns, are now folders in call number GR 1 VM 209, and Rice and Brown, American Campaigns, “Archives du Génie, 15- x – x” are now folders in GR 1 VN 7.
Three primary sources are critical to understanding the construction and modification of Butts Hill Fort:”
- Desandrouins (GR 1 VM 209) → baseline fort description
- GR 1 VN 7 materials → maps + letters
- Oyré letter (Sept 4, 1780) → strategic interpretation
1. File GR 1 VM 209 contains « mémoires, reconnaissances, projets de travaux de défense concernant … « including a detailed description by Colonel Jean Nicholas Desandroüins of the fortifications around Newport with identification of earthworks, French encampments and positions of ships in the harbor and notes in the left-hand margins. This is the most detailed description of the state of defenses around Newport at the arrival of French forces.
The description of Newport by Desandroins has been transcribed and translated. The description is available here:
SHD GR 1 VM 209 Desandrouins 1780 Newport defenses French
SHD GR 1 VM 209 Desandrouins 1780 Newport defenses English
The relevant section mentioning Butts Hill Fort begins:
To do one’s best to contest the ground was not enough, it was also necessary to provide the means of being rescued by ensuring communication with the continent. In this view, a fort called Boots-hill has been built on the height which dominates the interval between the two passages or ferry of Bristol and Howlands. The relief forces can assemble under its protection. This good work is of a high relief, well flanked, preceded by a ditch wide and deep enough, partly dug into the rock; it is sufficiently garrisoned with artillery and can contain 500 men.
This confirms Butts Hill Fort’s strategic role as a communications and reinforcement node between Rhode Island and the mainland.
2. GR 1 VN 7 contains « mémoires, plans, cartes sur les opérations de la guerre d’Amérique (1776-1781) »
The whole file is about 5 inches thick. One of the folders in the box is labelled “Guerre d’amerique (1776-1783, Nos 1-25).” The folder contains multiple maps of Boston, many British printed maps, i.e. Fadden &c. Item No. 3 is a manuscript by Querenet de la Combe, Journal du siege d’york en Virginie (avec 1 carte et plan), Faite au Camp d’York le 20 octobre 1781. (There is a copy of that Journal in a file called “Journals and records of the campaigns of Rochambeau’s army, 1781-1782” Call Number mss HM 621 in the Huntington Library.
No. 19 is a journal of de Grasse campaign to Yorktown that includes long accounts of the battles of Brimstone Hill, the Battle of the Saintes in April 1782, and also a copy of the “Journal de mon voyage en amerique (3 March to 29 Sept 1780)” by the comte de Charlus, colonel en second of the Saintonge Infantry Regiment. The original (or another copy?) of this long (227 pages) journal is in Archives Nationales, Marine B4, 183. It was published by W. Jackman, A Middle Passage. The Journal of Armand-Charles Augustin de LA CROIX de CASTRIES (Boston: Athenaeum, 1970)
The file also contains a series of letters by Desandrouins listed in Rice and Brown, American Campaigns, vol. 1, p. 299, the letters by Crublier d’Opterre listed on p. 298, as well as one letter each by Lt Colonel Guillaume Querenet de La Combe and Henry Dominique Marius de Palys. Desandrouins’ letter from Porto Cabello, also in that file, is reproduced in Rice and Brown, American Campaigns, vol. 1, between pp. 92/93.
All letters in GR 1 VN 7 are transcribed and translated in the file “SHD GR 1 VN 7 Letters by Engineers from Newport.” It is available here.
There is also a map of Rhode Island and description by Desandrouins in GR 1 VN 7. The main text is the same as GR 1 VM 209 but the manuscript lacks the explanatory notes of GR 1 VM 209. The map in GR 1 VN 7 has the title, »Plan de la Position de l’Armée Françoise au tour de Newport et du Mouillage de L’Escadre dans la Rade de cette Ville. » It is signed by Desandrouins.
It accompanies the Mémoire Sur la ville de Newport en Rhode-Island by Desandrouins describing the defenses around Newport as they existed in the fall of 1780. This memoire has not been translated since it is identical to File GR 1 VM 209. A transcription of the map legend is in file Butts Hill Fort Map 1 VN 7.
There is a manuscript copy of this map with identical numbers identifying the campsites of Rochambeau’s army, earthworks and vessels on the website of the Library of Congress.
That map, which is not attributed to Desandrouins, could be/should be used in connection with the file Butts Hill Fort Map 1 VN 7 which transcribes and translated the map legend.
There is a second map with the title »Plan de la disposition des Français dans Rhode-Island juillet et mois suivante 1780 » in MS A 224, ‘Atlas de la Guerre d’Amérique,’ Map 66. It has the same numbering to identify locations as this map, but it is unsigned. Numbering for that map is in file Butts Hill Fort Map 66.
The third important set of data for the reconstruction of Butts Hill Fort is…
3. A letter by French engineer François Ignace Ervoil d’Oyré dated 4 September 1780 in Dossier M//1021 in the Archives Nationales, Paris.
Dossier M//1021, Ordres militaires, hospitaliers, Universités, collèges. The wrapper of Folder IV has the title :
Lettres des diverses officiers prenant part a guerre d’Amérique, adressées au comte de Chastellux, mestre de camp dans le régiment de Beaujolais, à Versailles (1779-1782).
The next sheet reads :
Marine. Colonies Correspondance sur la Guerre d’Amérique
Lettres des Chevaliers de Chastellux de Ternay et autres au comte de Chastellux de 2 janvier 1779 au mois de Mar[s]. 1783.
Part IV contains dozens of letters from America to the comte de Chastellux. Philippe Louis, comte de Chastellux (1726-1784), colonel of the Régiment de Beaujolais and older brother of the chevalier François Jean de Chastellux (1734-1788) who served under Rochambeau in America. François Jean inherited the title marquis upon the death of his older brother Charles-François de Beauvoir in 1784.
There are a total of 43 letters. Some of the letters were written by French officers serving in the army of the comte de Rochambeau, especially by Charles Louis de Secondat, baron de Montesquieu, who served as an aide-de-camp to the chevalier de Chastellux in America. The majority of the letters were sent by officers who served in the Beaujolais Regiment. The letters from officers in Rochambeau’s army report on the stay in Rhode Island but the vast majority were written during the Yorktown Campaign, including the siege, but there are also a few from the march back to Boston in 1782, and embarkation to the West Indies.
The officers of the Beaujolais regiment served as garrison, i.e., supplementary infantry, on Le Citoyen and the St. Esprit, two SOLs in the fleet of Admiral de Grasse. They report in great detail to their colonel on the Yorktown Campaign and the subsequent campaign in the West Indies in 1782, esp. the capture of Brimstone Hill and the Battle of the Saintes in April 1782. Of particular interest are the reports by capitaine en second Jacomel de Chauvigny to Chastellux on the administration of his company, equipment, losses, replacements, etc.
The letters are not in exact chronological order in the file. Envelopes with addresses are missing; many of the letters, esp. those addressed to “my nephew” are not signed. All letters containing information on Newport and Butts Hill Fort have been transcribed and translated into ANF M 1021 Folder IV. Synopses for the other letters are included in the file.
Photographs of the French originals are here. The correct citation for these letters is: Archives Nationales de France, Cote M//1021, Paris, 1780-1783.
Only four letters were written from Rhode Island between July 1780 and June 1781 – three in the fall of 1780 (two of them by Charles Louis de Secondat, baron de Montesquieu, an aide-de-camp to the chevalier de Chastellux) and a third letter by Montesqiueu from Providence 15 June 1781. Of interest is a long letter by Oyré dated Newport, 4 September 1780, with a description of the French encampment and earthworks and fortifications around Newport. Though it does not mention Butts Hill Fort by name Oyré refers to it when he writes:
As for the eastern channel, which can be sailed by frigates, its outlet on the eastern roadstead is defended by batteries on both sides of Hollands Ferry, and by a large work placed on a height between this passage and that of Bristol. This point is of import for preserving the communication of Rhode Island with the continent.
There is also a brief description of defenses around Newport by Montesquieu (in the context of a British fleet appearing off the coast in August 1780) in a letter dated 12 October 1780, but in all of his letters Montesquieu is primarily pestering the comte de Chastellux for support for promotion to colonel-en-second of a regiment of Line Infantry.
These files held no information of relevance to the Butts Hill Fort project.
4. GR 1 VM 17 contains « mémoires, reconnaissances, projets de travaux de défense concernant … les États-Unis d’Amérique (1718-1928). There was nothing of note for our project in these files.
5. GR 1 VC-8, documents historiques sur les ingénieurs. The file would be of interest to someone writing a history of the French Corps of Engineers. The personnel files begin in 1697. None of the files held information relevant for Butts Hill Fort. Here are a few samples:
6. Desandrouins has a file in there (# 60), but it only covers his career up to 1762 and the end of the Seven Years’ War. Mostly concerning his career in Canada. There is also a personnel file in Papiers Désandrouins, Call No. GR 4 YD 3251 Marechaux de camp (ancien regime). The second part of this file begins with a letter dated 8 June 1761 awarding Desandrouins a pension of 200 livres for his services in Canada. The remainder of the file is mostly requests for promotions (his commission as Brigadier is included) and pensions, including one dated 1 July 1783 for 2,400 livres for having saved 254 soldiers left behind on the 74-gun-ship Bourgogne was wrecked on 4 February 1783, off Curaçao. Does not include any info on the American War.
Garavaque has a file in there (# 73), but it only goes to 1774.
File # 84: divers 1778, contains Lettres de revenir en amerique, i.e., correspondence concerning the request by Congress to allow the engineers DuPortail, La Radiere, Laumoy and Gouvion to stay in America for another campaign. The original letters (only in transl.) were sent by Congress 4 December 1778\January 1779
File # 93 is an Etat des graces accordees aux officiers du corps pour la siege de Yorktown, a list of rewards granted the engineers for their services during the siege of Yorktown.
7. GR 1 VC-17, formations et organization du corps du genie: mémoires, notes [&c] 1775-1788, which deals with organizational changes due to the army reforms of Germain.
8. GR 1 VC 4-6, États des ingénieurs et des officiers (ordre alphabétique). 1708-1817 is an alphabetical order of engineer officers, again only useful for someone who wants to write a history of the corps. The same applies to
9. GR 1 VC 10, Appointements des ingénieurs, états des ingénieurs décédés et appointements, traitements extraordinaires, indemnités, gratifications, pensions accordées à titre de retraite ou de récompense : états, correspondance
10. GR 1 VC 23-24, Habillement, équipement, port des outils et organisation des sapeurs et des mineurs : correspondance, mémoires, décret, règlements et instructions. I looked at No. 24: 1754-1816. This correspondence about uniforms, memoranda about new rules and regulations (ordonnances), debates on why geographers should not be in the engineer corps, tools and equipment, etc.
11. GR 1 VM 117, Sièges des places étrangères. The files date mostly to the 19th century. These is, however, a huge (maybe 6 feet by 4 feet) map by Desandrouins of the entry into Chesapeake Bay, but the rest is much later.
12. GR 1 VN 117, Sièges des places étrangères; contains Yorktown (1781-1782), has some great maps but pretty much all about Yorktown., e.g., No.1: Querenet de la Combe’s journal and two maps, No. 2 is his journal of the siege of Yorktown, but No. 3 is a plan for attack on New York. (Author unknown)
13. In the Private Archives at SHD, I looked at the papers of Palys-Montrepos, DE 2018 PA 120. They only contain a fragment of a longer write-up about the history of the War of Independence that Palys (?) compiled about the campaign of 1778 (Stony Point is mentioned) and d’Estaing coming to the U.S.
14. Recueil de plans de sièges et positions fortifiées durant la guerre de l’indépendance américaine aux Etats –Unis (1780-1782) is digitized and available in the reading room of SHD.
Its nine maps contained no relevant information for our project:
Plans de Rhode-Island (1), de la route de l’armée depuis Newport jusqu’au siège d’Yorck (2), du camp de Philipsbourg dans les plaines Blanches, occupé par les armées françoise et américaine du 6 juillet au 19 aout 1781 (3), des reconnaissances de King’s-Bridge (4), de Wespoint du nord (5), du siège d’Yorck par l’armée combinée, commandée par les généraux Washington et le comte de Rochambeau, en 1781 (6), de Wespoint en Virginie (7), du camp de Pisk-Kill et de la position de l’armée française, le 16 septembre 1782, et celle de Son Excellence le général Washington en 1780 (8), de Crompond occupé par l’armée française depuis le 24 septembre jusqu’au 22 octobre 1782 (9).
Access the collection here.
As was to be expected, the information gleaned from the many manuscripts and maps varied greatly. Three manuscripts stand out, however, in their importance for our understanding of Butts Hill Fort. One is a very detailed description of the fort in late 1780 in file GR 1 VM 209 that formed part of a report French Chief Engineer Desandrouins sent to France. The map drawn and signed by Desandrouins to accompany this account is in GR 1 VN 7.
The other important source is a letter by French engineer Oyré dated 4 September 1780 in Dossier M//1021 in the Archives Nationales.
These sources provide the most detailed contemporary descriptions of Butts Hill Fort currently identified and form a critical foundation for accurate historical reconstruction.
The author thanks the Archives du Génie in the Service Historique de la Defense in Vincennes for permission to reproduce maps and documents in their collections and the Archives Nationales de France in Paris for permission to reproduce letters to comte de Chastellux from M 1021 Folder IV.
June 2026
Robert A. Selig, PhD
- Desandrouins (GR 1 VM 209) → baseline fort description
- GR 1 VN 7 materials → maps + letters
- Oyré letter (Sept 4, 1780) → strategic interpretation
- The Battle of Rhode Island: Skirmish Timelines and Map
- Skirmish at West Main Road and Union Street
- Skirmish at East Main Road and Union Street
- Turkey Hill
- Quaker Hill
- Lehigh Hill
- The Gaspee Affair: A Rhode Island Perspective on Its 250th Anniversary
- The Conspiracy to Destroy the Gaspee
- Patriot’s Retreat to Tiverton
- Significant People
- Eyewitness Accounts
- The Aftermath of the Battle
