Tensions between England and the United States had been building for years, particularly since the start of the Napoleonic War in 1803. Contending with England, Napoleon, in 1803, sold to the United States all French territory west of the Mississippi River. Termed the Louisiana Purchase, the sale helped subsidize the French war effort, and more than doubled the size of the United States. The purchase agreement also gave the United States some lands disputed with England along the Canadian border.
At war with France, England faced a growing problem of desertions, particularly from the Royal Navy. To recover deserters, England implemented a policy of boarding vessels encountered, and impressing any deserters found aboard. Frequently, the British boarded American trade ships and seized crew members, including American citizens falsely identified as former British sailors.
