The Louisiana Purchase of 1803 transferred a vast territory to the United States from France.
President Thomas Jefferson’s administration negotiated the purchase with France, then led by First Consul Napoleon Bonaparte. The United States agreed to pay 60 million francs and assume claims by American citizens against France, for a total value commonly estimated at about $15 million.
The agreement gave the United States control of approximately 828,000 square miles west of the Mississippi River, including the port of New Orleans. The purchase roughly doubled the nation’s territory and strengthened American access to the Mississippi River and the Gulf of Mexico.
France had regained Louisiana from Spain shortly before the sale, but Spain was not the seller in 1803. The purchased territory was later organized into states and territories, including Louisiana, Missouri, Arkansas, Iowa, and parts of many western states.