Which 1781 event ended the major land fighting of the American Revolution?

The Siege of Yorktown ended the major land fighting of the American Revolution in 1781.

American and French forces surrounded the British army at Yorktown, Virginia, during September and October 1781. George Washington commanded the Continental Army, while the Comte de Rochambeau led French troops on land and the Comte de Grasse's fleet blocked British relief by sea. Cornwallis's position became untenable after allied artillery captured key defensive redoubts.

Cornwallis's army formally surrendered on October 19, 1781. The event was the last major land engagement of the war, but it did not immediately create a peace treaty. Fighting continued in some places, especially at sea, while diplomats negotiated. The Treaty of Paris, signed in 1783, formally recognized U.S. independence. Yorktown is sometimes called simply the Battle of Yorktown, but “siege” better describes the sustained encirclement and bombardment that forced the surrender.