In 1763, after Great Britain defeated France in the French and Indian War (part of the Seven Years' War), it took possession of the French territory in North America east of the Mississippi River, including Prairie du Chien. During the American Revolutionary War, the city was used as a meeting point for British troops and their Native American allies. After the American victory, the Treaty of Paris (1783) granted the area to the new United States of America, but the British and their Loyalists were slow to withdraw. Only after the War of 1812 did the city become fully American.