The Siege of Yorktown is regarded as the last major campaign of the American Revolution linked to America250.
The siege took place in Virginia from September 28 to October 19, 1781. American forces led by George Washington and French forces commanded by the Comte de Rochambeau surrounded the British army under Charles Cornwallis.
French naval control in the Chesapeake helped prevent British relief. After sustained bombardment and the capture of key defensive positions, Cornwallis surrendered at Yorktown. The victory badly weakened Britain’s ability to continue large-scale operations in North America and encouraged peace negotiations.
Yorktown did not instantly end every military action. Fighting and diplomatic negotiations continued afterward, and the Treaty of Paris was signed in 1783. The siege is called the last major campaign because it was the decisive large-scale operation, not because every later event stopped immediately.