The 1781 siege that became the final major land engagement of the American Revolutionary War was the Siege of Yorktown.
American and French forces surrounded the British army commanded by General Charles Cornwallis at Yorktown, Virginia. George Washington led the Continental Army, while French troops served under the Comte de Rochambeau. French naval forces under the Comte de Grasse blocked British relief by sea after defeating a British fleet at the Battle of the Chesapeake.
The siege began on September 28, 1781. Allied troops captured two important British outer redoubts on October 14, allowing them to move their artillery closer. Cornwallis requested terms two days later, and the British surrender ceremony took place on October 19. Cornwallis himself did not attend the ceremony.
Yorktown did not immediately end all fighting, and the Treaty of Paris was not signed until 1783. However, the surrender prompted serious peace negotiations and effectively ended major combat on land. It is often confused with the Battle of Saratoga, an earlier American victory that helped bring France into the war.