Which 1781 campaign forced the largest British army in the American Revolution to surrender?

The Siege of Yorktown forced the largest British army in the American Revolution to surrender in 1781.

American and French forces surrounded British troops commanded by General Charles Cornwallis at Yorktown, Virginia. General George Washington led the combined American army, while the French army was commanded by the Comte de Rochambeau. The siege began in late September 1781.

French naval success was essential. Admiral de Grasse’s fleet defeated or blocked British naval forces in the Battle of the Chesapeake, preventing Cornwallis from receiving effective relief or escaping by sea. Allied artillery then tightened the lines around the British position.

Cornwallis surrendered on October 19, 1781. Fighting continued elsewhere, but Yorktown was the last major campaign of the war. Peace negotiations led to the Treaty of Paris in 1783, which formally recognized American independence.