How did the French fleet at the Battle of the Chesapeake help the Marquis de Lafayette’s forces at Yorktown?

The French fleet, commanded by the comte de Grasse, was instrumental in the success of the Marquis de Lafayette’s forces at Yorktown by securing control of the Chesapeake Bay and preventing British reinforcement or escape by sea.1

Following their victory at the Battle of the Chesapeake, the French fleet provided essential protection for the transport of General George Washington’s armies down the Chesapeake Bay to Williamsburg. Once there, these troops joined the allied forces already under Lafayette’s command.1

By decisively outnumbering the British fleet and forcing them to retreat to New York, the French naval victory effectively sealed the fate of Lord Charles Cornwallis at Yorktown. Deprived of the expected resupply and relief by water, Cornwallis was unable to break out of his position and was compelled to surrender on October 19, 1781.1