During the 1781 siege of Yorktown, a fleet of 27 French ships-of-the-line under the command of Adm. Paul Compte de Grasse blocked any chance for the British army to escape by sea by blockading the Chesapeake Bay. A British fleet, nominally under the command of Rear Adm. Lord Thomas Graves, engaged the French fleet in an attempt to break the siege. After a battle that lasted several hours, Graves and the British fleet failed in their task and they withdrew. British forces at Yorktown surrendered to French and Patriot ground forces a short time later, paving the way for the Treaty of Paris in 1783.
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