Horvath wrote

The last battle was at Yorktown. Cornwallis was under seige, and
awaiting reinforcements. The French fleet cut off the ships bringing
those reinforcements, giving the victory to Washington. Didn't you
notice the French ships in the harbor near the end of that last
battle?

http://www.mariner.org/usnavy/03/03e.htm

Very little was written about the "Battle of the Capes" between
the British and French Fleets at the mouth of the Cheasepeake
Bay. The Brits really screwed this one up by not engaging the
French. The French fleet successfully defended their postion.
After dancing around for a few days, the French were reinforced,
and the slightly outnumbered British fleet chickened out and ran
away.

On land Cornwallis was pinched off, and surrendered six weeks
later--entirely due to the British Navy's failure to engage and
fight the French decisively when they had the chance.

All Americans owe British Rear Admirals Hood, and Graves and
Prime Minister Lord North--the notable "Brit's who quit", that
threw in the towel, and our gratitude to French Rear Admiral de
Grasse for this relatively minor battle which had enormous
strategic implications.

Bart Senior