In June 1780, Gen. George Washington told a lie. In fact, he planned a major deception. But as it was intended to deceive the British high command during the midst of the Revolutionary War, most Americans would likely forgive him. General Washington, with the aid of Major General Lafayette, wanted the British to believe that the French army under the command of Lieutenant General Rochambeau, soon expected to arrive in North America, was intended to help the Americans liberate Canada from the British yoke.
Washington and Lafayette designed a proclamation that they planned to have printed in Philadelphia. “We talked of a Proclamation to the Canadians,” Washington wrote to Lafayette in May, “If it is not already done, I think it ought not to be delayed. It should be in your own name, and have as much as possible an air of probability.” Washington wanted to use the document (to be written in French) to propagate an elaborate ruse. The proclamation, the American commander wrote, “should contain an animating invitation [to the Canadians] to arrange themselves under the allied banners. … you should hold yourself up as a French and American officer charged both by the King of France and by Congress with a commission to address them upon the occasion. It may indeed be well to throw out an idea that you are to command the corps of American troops destined to cooperate with the French armament. The more mystery in this business the better. It will get out and it ought to seem to be against our intention.”
In late May Lafayette was busy drafting the proclamation. He explained to the Chevalier de La Luzerne, French minister in Philadelphia, who was to be in on the secret of the deception, that the purpose of the missive was to “mislead the enemy” on the aim of the Continental army’s joint operations with Rochambeau’s force. “This document will be printed in the greatest secrecy, but we shall take care to pass it on to New York,” he explained. (British headquarters in North America was located in New York City.) Once the French army actually arrived, the documents would be “thrown in the fire.” The whole purpose was for the “secret” printing of the document, and it contents, to leak out in Philadelphia and make its way to Gen. Henry Clinton, the British commander in chief, who would then hopefully direct his efforts to defending that province instead of Washington’s real objective, New York City. Lafayette even asked La Luzerne for a stamp with the arms of Louis XVI, King of France. If he could place the king’s arms on the proclamation “it could help to deceive the enemy’s spies even more.”
By early June, Lafayette had a draft of the proclamation finished, and Washington forwarded it to the military commander in Philadelphia. The chief Continental officer in that city at the time happened to be Maj. Gen. Benedict Arnold. On the 4th of June, Washington wrote to Major General Arnold from his headquarters at Morristown, N.J.: “Dear Sir … You will be pleased to put this into the hands of a printer whose secrecy and discretion may be depended on and desire him to strike off a proof sheet with the utmost dispatch … The importance of this Business will sufficiently impress you with the necessity of transacting it with every possible degree of caution.” Although the American commander had no inkling at this time that Arnold was a traitor, his caution in not revealing the “secret” led Arnold to believe the proclamation was genuine. In a few days, Arnold, after some difficulty finding a printer who could be trusted, had a proof sheet of the proclamation printed and sent it to Washington’s headquarters for final corrections. At the end of June, the American commander returned the proof sheet, with corrections (presumably done by Lafayette) to the printer.
Arnold had been in communication with Maj. John André, Clinton’s adjutant general, for over a year. Arnold sent his letters to André through a system of intermediaries. Loyalist Joseph Stansbury acted as Arnold’s chief contact in Philadelphia, and the Loyalist Rev. Jonathan Odell received them in in New York City for André. While André was with Clinton on an expedition to capture Charleston, South Carolina, in the spring of 1780, Capt. George Beckwith, aide to the acting commander in New York City, received Arnold’s missives.
Arnold, in addition to having the proof struck, immediately advised Beckwith of the proclamation and sent him the text of the document. On June 7, Arnold, using his code name “Mr. Moore” wrote the British captain (via Stansbury): “I have received from The Commander-in-Chief a Proclamation in order to have a number of Copies printed, the purport of which, will be transmitted to you by J:S: [Stansbury] to whom I have communicated it. … The American Army intended to cooperate with the French will probably go up Connecticut River to Number Four and cross the Country to St Johns.”
Other elements of the deception transpired just as Washington and Lafayette hoped (though they had no idea Arnold would be the vehicle). The French ambassador played his role perfectly. Arnold wrote Beckwith: “The Minister of France this day assured me that the French Troops destined for Canada amount to Eight Thousand.” Stansbury converted Lafayette’s proclamation to code and sent it, with Arnold’s letter, to Beckwith, commenting that the proclamation “must be a profound secret.”
Arnold thus unwittingly served Washington’s purpose: to get the proclamation into the hands of the British commander in chief and create the impression that the expected French army was intended for an attack on Canada. Thanks to Arnold’s treachery, Washington’s deception had succeeded.
 Washington to Lafayette, May 19, 1780, U.S. Library of Congress, George Washington Papers (DLC:GW).
 Lafayette to the Chevalier de La Luzerne, May 25, 1780, in Stanley J. Idzerda et al, eds., Lafayette in the Age of the American Revolution Selected Letters and Papers, 1776-1790, 5 vols. (Ithaca and London: Cornell University Press, 1977-83), 3:35.
 Ibid. Idzerda notes that although La Luzerne agreed to the request, the king’s arms did not appear on the printed proclamation.
 Washington to Arnold, June 4, DLC:GW. The enclosed draft of this proclamation has not been identified.
 Arnold to Washington, June 7, 1780, Pennsylvania Historical Society: Gratz Collection. The corrected proof sheet that Washington sent to the printer has not been identified; but there is a hand-corrected proof sheet of the proclamation (in French) in the Nourse Family Papers (3490-a) at University of Virginia’s special collections library.
 For more on this chain of communication, see Carl Van Doren, Secret History of the American Revolution: An Account of the Conspiracies of Benedict Arnold and Numerous Others drawn from the Secret Service Papers of the British Headquarters in North America now for the first time examined and made public (New York: The Viking Press, 1941), 196-201.
 Arnold to Beckwith, June 7, 1780, in Van Doren, 459-60.