How much land did the United States acquire through the Louisiana Purchase?

The United States acquired approximately 828,000 square miles through the Louisiana Purchase in 1803.

President Thomas Jefferson’s administration purchased the territory from France for $15 million. The agreement transferred a vast region west of the Mississippi River and east of the Rocky Mountains, including the port of New Orleans. The acquisition nearly doubled the size of the United States.

The territory did not correspond neatly to modern state boundaries. It included all or parts of 15 present-day U.S. states and two Canadian provinces. The purchase therefore refers to a historical territorial transfer, not to the modern state of Louisiana alone.

France had regained Louisiana from Spain in 1800, but Napoleon Bonaparte abandoned plans for a large North American empire after renewed war with Britain and the failure of French forces to suppress the Haitian Revolution. The sale gave the United States control of the Mississippi River system and opened enormous areas to later American expansion, while also intensifying conflicts over Indigenous sovereignty and slavery.