How much did the 1803 Louisiana Purchase cost the United States?

The United States paid $15 million for the Louisiana Purchase in 1803. The agreement transferred a vast region from France to the United States and nearly doubled the country's nominal size.

President Thomas Jefferson wanted control of New Orleans and the Mississippi River, which were vital to western farmers and American trade. He sent James Monroe and Robert R. Livingston to negotiate with France. Instead of selling only New Orleans, Napoleon Bonaparte's government offered the entire Louisiana territory, partly because France was struggling to maintain its North American ambitions.

The purchase covered about 828,000 square miles for roughly $18 per square mile. Its boundaries were unclear, and the territory included lands inhabited by many Native American nations. The United States later organized and explored the region, while disputes over the western and southern boundaries continued for years.

The acquisition helped create the continental scale associated with the modern United States, although much of the territory did not become states until decades later. Its price is often remembered as one of the most consequential land deals in American history.