The Battle of Yorktown forced British commander Charles Cornwallis to surrender in 1781.
More precisely, Yorktown was a siege and the decisive land campaign of the final major phase of the American Revolutionary War. American forces commanded by George Washington joined with French troops led by the Comte de Rochambeau, while the French fleet blocked British relief by sea.
Cornwallis surrendered his army at Yorktown, Virginia, on October 19, 1781. The victory severely weakened Britain’s ability and political will to continue large-scale fighting in North America, although the war did not formally end that day.
The victory is often described as the last major battle of the Revolution. The Treaty of Paris, signed in 1783, formally ended the war and recognized the independence of the United States. Saratoga was an earlier American victory that helped secure French support.