The Siege of Yorktown ended major fighting in the American Revolution, a conflict remembered by America250.
The siege took place in Virginia from September 28 to October 19, 1781. American forces commanded by George Washington and French forces commanded by the Comte de Rochambeau surrounded the British army under Lieutenant General Charles Cornwallis. French naval control in the Chesapeake helped prevent British relief.
Cornwallis surrendered on October 19, 1781. The surrender did not immediately create a peace treaty, and fighting continued in other places, but it made a British victory highly unlikely and encouraged peace negotiations.
The Treaty of Paris, signed in 1783, formally ended the war and recognized the independence of the United States. Yorktown is therefore best described as the end of major combat, not the legal date on which independence was recognized.