The Siege of Yorktown forced the British army under Charles Cornwallis to surrender during the American Revolution.
The siege took place from September 28 to October 19, 1781, at Yorktown, Virginia. American forces led by George Washington worked with French troops commanded by the Comte de Rochambeau. French naval forces also blocked British relief by defeating a British fleet at the Battle of the Chesapeake on September 5, 1781.
The allied army surrounded Yorktown and built progressively closer siege lines. After the capture of key British defensive positions, Cornwallis recognized that his army could not escape or receive effective relief. He surrendered on October 19, with roughly 8,000 soldiers becoming prisoners.
Yorktown did not immediately create a peace treaty, and fighting continued elsewhere. However, the surrender badly weakened British political support for continuing the war. Peace negotiations produced the Treaty of Paris in 1783, which formally recognized American independence. Yorktown is therefore often called the last major battle of the American Revolutionary War.