A legend has been created by some who promote the story that de Grasse was persuaded to take his fleet to the Chesapeake due to the visit of an American Lt Col Allan McLane, who in July 1781, boarded admiral de Grasse's Ville de Paris, reportedly with a dispatch from General Washington. During the brief visit with the French admiral, Col. McLane expressed his opinion that de Grasse should proceed with his fleet to the Chesapeake.
Should any such encounter have taken place, it certainly would not have been the pivotal moment in de Grasse's decision to make his epic deployment to go to the Chesapeake in August 1781. The few narratives that emphasize this event place their evidence on very suspect claims of hearsay witnesses, and seriously ignore the more proven evidence that de Grasse already had in his hands written authority and suggestions to go to the Virginia coast from far more distinguished persons. De Grasse had already received dispatches written by Rochambeau and La Luzerne – both from individuals who would be well recognized by the French admiral.
The story finds its way around a varity of home-spun American authored folk narratives, which exhibit an ignorance of the fact that de Grasse had with him far more impersuasive arguments for going to the Virginia coast. In particular, the legend ignores the instructions de Grasse was given by the French ministers and important appeals made to de Grasse from Rochambeau and La Luzerne. The legend attributing the French admiral's decision to an American captain seems to be based upon a ‘journal' that cannot be located. Evidence to discount the impact of McLane's visit [if it had ever occured] is well established.
Vergennes launched the second phase of his grand scheme to deploy more French forces to north America in early 1781, when he directed the large French fleet under admiral comte de Grasse be deployed to the Caribbean. De Grasse's mission was primarily to support French and Spanish interests in The West Indies, but his instructions also included assisting the allied land armies in North America where, and when, possible. Such alternative operational opportunities were quite conceivable given the practice of large naval forces to move away from the Caribbean waters during hurricane season – occurring largely during August and September. Mindful of his instructions, de Grasse wrote a 29 March 1781 dispatch to Rochambeau, even before the French fleet reached the West Indies, requesting to be informed as to the strength and position of the English armies in North America, in anticipation of being able divert to that theater in late July for a month or two. Such dispatches were sent on ahead by fast sailing packet ships, this one did not reach Boston until 10 June 1781.|
Rochambeau had been aware of de Grasse's deployment, but was cautioned by the French authorities to keep it a secret to lessen the risk of the British intercepting his convoy. The topic of a French naval force coming to North America was discusses in only theoretical terms at the 1781 May Wethersfield conference with George Washington. Immediately after that conference, Rochambeau sent a 28 May dispatch to de Grasse -- these were followed by 31 May and 6 June dispatches. Rochambeau informed de Grasse that the admiral's arrival "may save the situation" and listed badly needed resources of money to pay troops and more land forces in addition to the naval superiority which the French fleet can furnish. Rochambeau went on to states: "There are two points where the enemy can be attacked: the Chesapeake, and New York. . . . You will probably prefer Chesapeake Bay, and it is there we think you can render the greatest service."
De Grasse arrived at Cap-Haïtien (formerly Cape Français) on 16 July, where he found awaiting him dispatches from Washington, Rochambeau, and the highly respected chevalier de la Luzerne, which mostly suggested the benefits of the French fleet going to the Chesapeake.
Rochambeau to de Grasse, May 28 and 31, June 6, 1781 in Doniol v, 475. Rochambeau to de Grasse, June 11, 1781in Doniol, v, 489.