 In 1803, war resumed between France and Britain, and with the Royal Navy firmly in control of the seas, reinforcements and supplies for Rochambeau never arrived in sufficient numbers.To concentrate on the war in Europe, Napoleon signed the Louisiana Purchase in April, selling France's North American possessions to the United States.The Haitian army, now led by Dessalines, devastated Rochembeau and the French army at the Battle of Vertières on 18 November 1803.