Concerns the beginning of the Yorktown campaign. He states he will leave with 25 to 29 warships on August 3 to Chesapeake Bay, and that he can remain no longer than the 15th of October. The postscript, in the handwriting of de Grasse, relates to the furnishing of pilots for Chesapeake Bay. This letter is listed and reproduced in The American Campaigns of Rochambeau's Army 1780, 1781, 1782, 1783, trans. and ed. by Howard C. Rice, Jr., and Anne S. K. Brown, Vol. I, pp. xvii-xviii and between pp. 60 and 61. It was exhibited at the National Museum of American History, Smithsonian Institution, in the 1981 exhibition, "By Sea and Land: Independence with the Help of France."