The Louisiana Purchase

In 1803, the United States was just 20 years old. There were 17 states in the Union and the American territory reached only as far West as the Mississippi River.
On the other side of the Mississippi between the river and the Rocky Mountains, was the unexplored Louisiana Territory. In 1800 Napoleon, emperor of France had taken Louisiana back from Spain who ruled it since 1763.
President Jefferson did not want the French army threatening America's western boarder. …