Benedict Arnold was initially a hero of the American Revolution but later committed treason by offering to hand over the key fort of West Point to the British. The British occupied Savannah, Georgia in 1778 and Charleston, South Carolina in 1780, where over 5,000 American troops were captured in the worst defeat of the war. Later battles including Cowpens and Guilford Courthouse involved clashes between American generals like Nathaniel Greene and Daniel Morgan against British commander Charles Cornwallis, ultimately resulting in Cornwallis' surrender at Yorktown in 1781 after being surrounded by American and French forces, effectively ending the Revolutionary War.