The story of the Louisiana Purchase begins with France and Spain. The two European countries wanted to limit the power of the United States. So, in 1800, Spain and France entered into a secret treaty. In the treaty, Spain gave France control of a large area in North America called the Louisiana Territory.

The Louisiana Territory stretched north-to-south from the Gulf of Mexico to Canada. And, it stretched east-to-west from the Mississippi River to the Rocky Mountains. The area was important not only for its large size. It also included some valuable navigation features, including where the Mississippi River opened into the Gulf of Mexico.

Napoleon Bonaparte ruled France at that time. Jefferson did not want Napoleon in North America. He felt the French presence was a threat to the peace of the United States. He decided to try to buy parts of the Louisiana Territory, especially around the mouth of the Mississippi River near the city of New Orleans.

Jefferson sent James Monroe to Paris as a special negotiator.

But Monroe never had a chance to offer the American position. Napoleon had decided to sell everything to the Americans. He told his finance minister to give up Louisiana -- all of it. Napoleon needed money for a war with Britain.

James Monroe was happy to negotiate the purchase of Louisiana. They agreed on a price of eighty million francs for all the land drained by the great Mississippi River and all its many streams.