After the British surrendered at Yorktown in 1781, the Treaty of Paris was ratified in 1783, recognizing the United States as an independent nation and establishing its borders from the Atlantic to the Mississippi River. The Americans won the Revolutionary War for several reasons: they knew the local geography, the British were fighting from far away in England, the Americans received military and financial assistance from France and Spain, and the American spirit of patriotism and desire for independence drove them to continue fighting despite early setbacks.