By the end of the month an army of sixteen thousand men, of whom about one-half were French, was besieging Cornwallis with seven thousand men in Yorktown.
Heart-stirring events had happened while the armies were marching to the South.

The Comte de Grasse, with his great fleet, arrived at the entrance to the Chesapeake on the 30th of August while the British fleet under Admiral Graves still lay at New York.

Grasse, now the pivot upon which everything turned, was the French admiral in the West Indies.
Taking advantage of a lull in operations he had slipped away with his whole fleet, to make his stroke and be back again before his absence had caused great loss.

It was a risky enterprise, but a wise leader takes risks.

He intended to be back in the West Indies before the end of October.
It was not easy for the British to realize that they could be outmatched on the sea.