American Spies and Sympathizers at Fort Detroit

By Geoffrey Hoerauf

Located far enough away from American controlled Fort Pitt and close to the majority of British-allied Indians, Fort Detroit became the center for the British military and Indian Department efforts in the Western Great Lakes, Southern Ohio, and Kentucky regions during the American Revolutionary War. As a result, Fort Detroit and the surrounding settlement became a "spring board" for British-allied Native American raids on American settlements in Kentucky and Western Virginia. Due to its location on the Great Lakes, Fort Detroit also served as a depot for Forts Michilimackinac and Saint Joseph, the Illinois settlements (Vincennes, Cahokia, and Kaskaskia), Miamitown, and the lands west of Lake Superior. The American government and military realized that if they could control the Detroit region then the British influence over the Native Americans in that region would diminish. This would hopefully reduce if not eliminate the pressures put on the American settlements in Kentucky and Western Virginia. In order to gain more information concerning the military and British Indian Department activities in the Detroit region, the Americans recruited inhabitants of the Detroit region as spies and sympathizers for the American cause.1

Shortly after the rebellion started, the British military became aware of American spies and sympathizers in the Detroit region. In Detroit on 23 August 1777, Lieutenant Governor Henry Hamilton issued orders that all strangers entering Detroit and any suspicious activity must be reported immediately to the military authorities.2 This evidently was an attempt to deter covert operations against the British at Detroit.

The first group the British military suspected of treason, with good reason, were the French habitants of the Detroit region. Although the British assumed control of Detroit in 1760, the French habitants (residents) represented the vast majority of people living in the Detroit settlement. The majority of these French had an active role in the fur trade throughout the Western Great Lakes region as well as areas located to the west and south of that area. As a result, the French habitants and the Native Americans in that region developed a strong relationship. Throughout the war, this relationship caused the British military and Indian Department to remain very suspicious of these two groups' relationship between themselves and their relationship with the British war cause. The British soon realized that the French habitants viewed the war as an Anglo civil war, and that it did not concern them. The French habitants' apparent lack of loyalty to the British cause constantly wor ried Lieutenant Governor Henry Hamilton. In mid 1778, Hamilton wrote that he believed "there is but one in twenty (French habitant), whose oath of allegiance would have force enough to bend him to his duty."3 This would remain true throughout the war.

The British soon realized that even British subjects living in the Detroit region supported the American cause. Hamilton reported that he had came to suspect some British traders' who "are rebels in their hearts".4 By August 1778, the lieutenant governor's impression had not changed when he wrote Lieutenant Governor Cramahe "The disposition of the (British) people at this place requires something more than the shadow of authority to keep them in the Bounds of Duty."5 In a latter letter, Hamilton wrote that "as to my knowledge the Enemies of the Crown are suppl'd or have been from this place, proofs of which I am possess'd of."6

After Lieutenant Governor Henry Hamilton's capture at Vincennes, the American supporters at Detroit put the military at Fort Detroit into a precarious situation. Lieutenant Colonel Mason Bolton, at Carleton Island, noted this fact when he wrote General Haldimand "in short Capt. Lernoult (the new British commander) has very little hopes of any assistance from either the Canadians or Indians. The latter are particularly industrious in debauching the minds of the former, and have succeeded too well".7 In response to this problem, General Haldimand authorized Captain Lernoult to apprehend anyone that directly or indirectly aided the Americans and their allies with either provisions or intelligence. Capt. Lernoult was than to transfer the prisoners to either Fort Niagara or Carleton Island. Additionally, the general wrote "And it is your duty to require and obtain from all Persons of doubtful character, such Hostages as may effectual prevent them, or any part of their family from taking an active part against His Majesty's Government or Troops under your Command."8

Capt. Lernoult immediately put his new powers into effect. One of the first trials involved James Cassedy and William Boslick, both farmers in the Detroit area. From 20-21 July 1779, both John Cassedy and William Boslick were accused of treason before Captain Lernoult and Captain Andrew Parke, 8th Regiment of Foot. Specifically Henrick Ingo, recruit in Captain Caldwell's Company of Rangers, stated he " has often heard the said John Cassedy together with one Wm. Boslick, speak in a very rebellious manner against the Government". In addition, Ingo stated that the two accused men stated that the Virginians would be in Detroit shortly, and they would not sell their leathers until that happened.9 William Miller, ship carpenter, stated that "James Cassedy with Wm. Boslick drink success to the Congress & the American Arms". Miller also reported that Cassedy and Boswell stated they would wait to sell their leathers to Americans.10 Both John Langht on and John Cornwell also presented similar evidence against Cassedy and Boslick. 11, 12

On 25 July 1779, Captain Lernoult issued orders to "seize the bodys (sic) of Gerard Cochran, Hatter, Bonavanture Trouvant, & Thomas Wiggins, Traders, as to have their bodys (sic) before me immediately & also to seize all their effects."13 Most likely Bonavanture Trouvant was Laventure Toucher, a trader out of the Illinois country that the British had long suspected of treason. In his testimony on 28 July 1779, John Cornwall accused Cockran, Wiggins, and Touche', listed as a "French man from Vincennes" of treason. Evidently, his testimony was strong enough to convicted at least the "French man from Vincennes, Touche'", most likely Laventure Toucher. Six days after Cornwall's testimony, Captain Lernoult ordered Laventure's goods seized. The amount of goods taken totaled 446 Pounds, 10 Shillings, and two pence.14, 15

The cases against Israel Ruland and John Edgar provide for a direct link to Colonel George Rogers Clark's involvement with Detroit spies and sympathizers. Both John Higgins16 and William Humphreys17 accused Ruland and Edgar of assisting in their fleeing from Detroit. According to Humphreys' testimony, Israel Ruland promised them "three Fuzees" if they would desert. In response to their acceptance of Ruland's offer, Humphreys and his comrades traveled to John Edgar's house. According to Humphreys testimony, Humphreys and others received "four loaves of bread, Powder, lead, and some Sugar, as likewise Breech Clothes & Leggins". Edgar took care of their old clothing, and Ruland directed them towards Miamitown, where Humphreys and Higgins were eventually captured. According to both men, Ruland stated that he received a dollar per day from Clark for this type of work. Ruland successfully escaped the British authorities and made it eventually to the American-controlled settlement of Vincennes (present day Vincennes, Indiana). Edgar was captured by the British and charged with "aiding and assisting prisoners to make their escape at Detroit."18 Edgar was transferred to Carleton Island and from there to Montreal. After Montreal, no record of his future exists.

In the Spring of 1781, some support for the American cause still existed in the Detroit. Major Arnet De Peyster, commandant at Detroit, wrote General Powell:
"I am sorry to say that the Canadians are not to be depended upon, I therefore cannot make any considerable detachment from this Garrison". Major De Peyster than reported that he was sending East "some Canadians &c who were taken in arms at the Miami & St. Joseph", and the next ship would contain "some who are rather dangerous People in this settlement."19
In the same year, Alexander McKee at the "Upper Shawnee Village" wrote Major De Peyster:
"a Shawanee Indian arrived at the lower village who is supposed to be a spy from the Rebels he was accompied (sic) from Post Vincent (Vincennes) by two Frenchmen suspected to be upon the same errand. One of them I am informed is gone to Detroit and carries letters with him"20.
The above examples represent just a few reports of spying, etc. that occurred on behalf of the Americans during the war. How much effect this had on the British war effort in the West remains unknown; however, the above evidence supports that it did hamper the British to some degree. The presence of American spies and sympathizers at Detroit continued to harass the British until they surrendered that post in 1796.


  1. G.R. Clark to Mason, 19 November 1779, Illinois Historical Collection, Vol. 13, pg. 146
  2. Orders, 23 August 1777, Henry Hamilton Papers, Clarence Burton Historical Collection, Detroit Public Library
  3. Lieutenant Governor Henry Hamilton to General Frederick Haldimand, 1778, Michigan Pioneer and Historical Collection (MPHC), Vol. 19, pg. 465
  4. Ibid
  5. Lieutenant Governor Henry Hamilton to Lieutenant Governor Cramahe, 12 August 1778, MPHC, Vol. 9, pg. 462
  6. Lieutenant Governor Henry Hamilton to General Frederick Haldimand, MPHC, Vol. 9, pp. 468-9
  7. Lt. Colonel Mason Bolton to General Haldimand, 20 May 1779, MPHC, Vol. 14, pg. 415
  8. General Haldimand to Captain Lernoult, 13 June 1779, MPHC, Vol. 9
  9. Deposition of Henrick Ingo, 21 July 1779, MPHC, Vol. 10, pg. 343
  10. Deposition of Willaim Miller, 21 July 1779, MPHC, Vol. 10, pg. 344-5
  11. Deposition of John Langthon, 21 July 1779, MPHC, Vol. 10, pg. 343-4
  12. Deposition of John Cornwall, 21 July 1779, MPHC, Vol. 10, pg. 345
  13. 25 July 1779, Thomas Williams Papers, Burton Historical Collection, Detroit Public Library
  14. Deposition of John Cornwall, 28 July 1779, MPHC, Vol. 10, pg. 346-7
  15. 3 August 1779, MPHC, Vol. 10, pg. 353
  16. Deposition of John Higgins, 23 July 1779, MPHC, Vol. 10, pg. 355-6
  17. Deposition of William Humphreys, 23 July 1779, MPHC, Vol. 10, pg. 356
  18. Brigadier General H. Watson Powell to Captain Robert Matthews, 4 December 1780, MPHC, Vol. 19, pg. 585
  19. Major De Peyster to Brigardier General Powell, 17 March 1781, MPHC, Vol. 19, pg. 585
  20. Alexander McKee to Major De Peyster, 15 July 1781, MPHC, Vol. 19, pg. 648