It was the letter that forced Washington to give up his dream of recapturing New York.
Gen. Jean-Baptiste Donatien de Vimeur, comte de Rochambeau, encamped with his French army at Phillipsburg on the Hudson River, received it on August 14, 1781 and showed it immediately to Gen. George Washington, whose headquarters was nearby. Written on July 28 by Adm. François Joseph Paul de Grasse, leader of the French naval force in the Caribbean, who had sent it by fast cutter to Newport, whence it had been forwarded to Rochambeau, it announced that de Grasse and his formidable fleet were en route to Chesapeake Bay, “the spot which seems to be to be indicated by you, M. le comte, and by MM Washington, de La Luzerne [French minister to the U.S.] and de Barras [leader of the French naval contingent in Newport] as the surest to effect the good which you propose.”
That “good” was the capture or destruction of a British force sizeable enough to bring the Revolutionary War to a successful end. Ever since the fall of 1776, when Washington had been forced to abandon New York City to the British, he had been convinced that New York was the only such target whose recapture could win the war – but the news that de Grasse and his fleet was going to the Chesapeake forced Washington to give up the dream of recapturing New York.
He did so in a way that illustrates, as well as any moment in his career, his pragmatic approach to leadership. On being informed of de Grasse’s destination, Washington did not fight the decision or try to change it; rather, he channeled his energies toward moving the combined Franco-American forces to the Yorktown peninsula in time to meet de Grasse there. He very quickly laid out a comprehensive, day-by-day marching plan, explaining to Rochambeau, “I have named no halting day because we have not a moment to lose.” And he sent off a flurry of letters to his commanders nearer Yorktown to ready them, instructing Lafayette,
You will immediately take such a position as will best enable you to prevent [the enemy’s] sudden retreat thro’ North Carolina, which I presume they will attempt the instant they perceive so formidable an Armament [as de Grasse arriving] …. You will be particularly careful to conceal the expected arrival of the Count, because if the enemy are not apprised of it, they [will stay] on board their transports in [Chesapeake] Bay, which will be the luckiest Cercumstance in the World.
Washington also had another thing to conceal. As his trusted chief engineer, the Frenchman Louis Duportail, advised him, “If the enemy perceive that we give up the idea of attacking New york they will reinforce Portsmouth Virginia may be before we can get there.” Washington and Rochambeau agreed: to prevent Gen. Henry Clinton in New York from sending reinforcements to Lt. Gen. Charles, Earl Cornwallis, whose troops and ships then controlled the Yorktown peninsula, they had to deceive Clinton into thinking they were still focused on assaulting New York.
After six years at war, the ruse that Washington had so often used to fool the British – constructing extra tents and lighting extra fires to make it seem that more troops faced them than actually existed – was shopworn. A new stratagem was needed. The key to it lay in recent British actions on the North (Hudson) River.
In mid-July, shortly after the French had trekked to the Hudson from Newport, Baron Ludwig von Closen, a Rochambeau aide-de-camp, noted in his diary that five British ships led by the sloop Savage had sailed near to Tarrytown, and “we feared immediately that their object was the seizure of some bread … that we were expecting to come from Peekskill,” where ovens had been built. Later that day von Closen learned that his fear was justified, as those British ships fired on three “little covered boats laden with bread for our army,” and from a nearby French warehouse took more bread and other items. But two days later, as the British ships were returning down the river with their booty, the French targeted them: “Our howitzers paid them such a tender adieu that the Savage … was seriously set on fire and half the crew threw themselves overboard,” Closen wrote, adding, “You can be sure that this little lesson will give these gentlemen a distaste for this kind of amusement, and that they will no longer crave our white bread.”
Washington’s plan called for French and American armies to cross the Hudson from east to west, well north of New York City, and then to turn southward and course in parallel through New Jersey to Philadelphia. The plan of march suggested a stopping place for the French Army at Chatham, New Jersey, that was perfect for Washington and Rochambeau’s deceptive purposes. Chatham was twenty-five miles directly west of New York City and an equivalent distance from Staten Island and Sandy Hook, the most accessible water approach to New York’s harbor. Washington noted in his diary why they were going to Chatham: “Hazens regiment being thrown over [crossed the Hudson River] at Dobbs’s ferry was ordered with the Jersey Troops to March & take Post on the heights between Spring field & Chatham & Cover a french Battery at the latter place to veil our real movement & create apprehensions for Staten Island.”
Washington and Rochambeau believed that the British would reason thusly: If the French and Continental armies were going to attack New York or Staten Island, they would make a more-or-less permanent base at Chatham, but if those armies were headed further south, the base would be temporary.
How to make the British think the Chatham base was a permanent one? The answer – as Rochambeau would note a few months later, in a pamphlet – was “to establish a boulangerie at Chatham,” a set of ovens for baking bread. He dispatched his quartermaster to the banks of the Raritan River area to buy up whatever bricks could be obtained – the French predilection for brick ovens was well known, and Rochambeau hoped that buying up bricks, which could have no other military purpose than to prepare ovens, would be noted by local Loyalists who would report it to Clinton. Washington for his part dispatched a Continental guard unit to watch over the French advance corps as they constructed the ovens, and he had some thirty boats on carriages accompany the troops. Washington aide-de-camp Col. Jonathan Trumbull, Jr. noted in his diary:
French ovens are building at Chatham in Jersey. Others were ordered to be prepared at a place near the Hook. Contracts are made for forrage to be delivered immediately to the French Army on their arrival at the last mentioned place. Here it is supposed that Batteries are to be erected for the security and aid of the Fleet, which is hourly expected. By these maneuvres and the correspondent march of the Troops, our own army no less than the Enemy are completely deceived.
When Rochambeau’s forces arrived at Chatham, the ovens were in operation in a sixty-five-foot shed, and producing 3,000 loaves of aromatic, crusty French bread per day.
The ruse worked like a charm. Although Clinton may have had a suspicion that the Chatham installation was meant to deceive him, he could not be certain; and furthermore, since he had no information on the whereabouts of de Grasse other than the knowledge that he had headed north from the Caribbean, Clinton could not risk sending troops to help Cornwallis, either by land or aboard warships, needing to keep both soldiers and ships in place in New York in case the French fleet suddenly appeared off Sandy Hook.
“This [boulangerie] maneuver prevented General Clinton from sending forces to the rescue of Cornwallis,” Rochambeau would definitively state. And Washington would much later recall,
That much trouble was taken and finesse used to misguide & bewilder Sir Henry Clinton in regard to the real object, by fictitious communications, as well as by making a deceptive provision of Ovens, Forage & Boats in his Neighbourhood, is certain. Nor were less pains taken to deceive our own Army; for I had always conceived, when the imposition did not completely take place at home, it could never sufficiently succeed abroad.
Through the final week of August, Clinton continued to believe that the French and Americans were still in Chatham; on August 30, he wrote to Cornwallis, “Mr. Washington’s force still remains in the neighbourhood of Chatham, and I do not hear that he has as yet detached to the southward,” and in a post-script written on September 1, he added, “Unless Mr. Washington should send a considerable part of his army to the southward, I shall not judge it necessary until then to detach [some of my forces] thither.”
And Washington kept up the deceit even as the armies departed Chatham, leaving behind not only the ovens, which continued to operate, but also American units to guard them. He wrote ahead to deputy quartermaster Col. Samuel Miles, near Trenton, directing him to collect and prepare boats to take the troops over the Delaware River from Trenton to Philadelphia, advising Miles,
I have delayed having these preparations made until this Moment, because I wished to deceive the Enemy with regard to our real object as long as possible – our movements have been calculated for that purpose and I am still anxious the deception should be kept up a few days longer, until our intentions are announced by the Army’s filing off towards the Delaware.
Even on September 2, when Clinton informed Cornwallis, “Mr. Washington is moving an army to the southward, with an appearance of haste, and gives out that he expects the co-operation of a considerable French armament,” and the British fleets then in New York prepared to sail for the Chesapeake, Clinton still reassured Cornwallis “that your Lordship will have little to apprehend from [the fleet] of the French.”
The alarm was raised too late, and the braggadocio was misplaced. Days earlier, de Grasse’s fleet had made the outskirts of Chesapeake Bay, just as Generals Rochambeau and Washington were entering Philadelphia ahead of the main body of their troops, and as Duportail was being rowed out to de Grasse’s flagship, Ville de Paris to convey the news that the French and American armies were en route down the Atlantic seaboard to link with his ships and begin the encirclement of Cornwallis and the battle of Yorktown. By the time Cornwallis received his superior’s note, his fate had already been sealed.
Neither then nor later did General Clinton ever acknowledge that he had been effectively tricked into complacency and into remaining with his forces in New York, rather than going to the relief of Cornwallis at Yorktown, by the British taste for French bread.
 De Grasse to Rochambeau, et al., July 28, 1781, in Henri Doniol, Histoire de la participation de la France a l’etablissement des États-Unis d’Amérique (Paris: Imprimerie Nationale, 1886-1892), 4:650-651.
 Washington to Rochambeau, August 17, 1781, https://founders.archives.gov/documents/Washington/99-01-02-06713
 Washington to Lafayette, August 15, 1781, https://founders.archives.gov/documents/Washington/99-01-02-06693
 Duportail to Washington, August 15, 1781, in E. S. Kite, Brigadier General Louis Lebegue Duportail, Commandant of Engineers in the Continental Army, 1777-1783 (Baltimore: The Johns Hopkins Press, 1933), 202.
 Ludwig Von Closen, The Revolutionary Journal of Baron Ludwig von Closen, translated by Evelyn Acomb (Chapel Hill: University of North Carolina Press, 1958), 95.
 Ibid, 97.
 Washington Diary entry, August 19, 1781, http://founders.archives.gov/documents/Washington/01-03-02-0007-0004-0013
 John Baptise Donatien de Vimeur, Comte de Rochambeau, Relation, ou Journal
des opérations du Corps Français sous le commandement de Comte de
Rochambeau, Lieutenant-Génèral des Armées du Roi, depuis le 15 d’Août
1781 (Philadelphia: Guillaume Hampton, 1781).
 “Minutes of Occurrences respecting the Siege and Capture of York in Virginia, extracted from the Journal of Colonel Jonathan Trumbull, Secretary to the General, 1781,” Proceedings of the Massachusetts Historical Society 14 (1875-76): 331–38.
 Although the exact location of the ovens is not known, the French encampment was in the area of what is today Shephard Pollock Park in Chatham.
 Rochambeau, Relation.
 Washington to Noah Webster, July 31, 1788, http://founders.archives.gov/documents/Washington/04-06-02-0376
 Clinton to Cornwallis, August 30-September 1, 1781, Correspondence Between His Excellency General Sir Henry Clinton, K.B., and Lieutenant General Earl Cornwallis (New York, 1781), 45-46.
 Washington to Samuel Miles, Aug. 27, 1781, http://founders.archives.gov/documents/Washington/99-01-02-06801
 Clinton to Cornwallis, Correspondence, 46-47.