Louisiana Purchase — 1803 acquisition by the U.S. of France's claim to the territory of Louisiana
The Louisiana Purchase nearly doubled U.S. territory, acquiring 828,000 square miles from France for $15 million and shaping the nation's westward expansion.
Key Facts
- Purchase price
- $15 million
- Area acquired
- 828,000 sq mi (2,140,000 km²)
- Cost per square mile
- Approximately $18 USD/sq mi
- Share of contiguous U.S.
- More than 26% of present contiguous U.S.
- Non-native population at purchase
- ~60,000 inhabitants, ~half enslaved
- States fully included
- Arkansas, Missouri, Iowa, Oklahoma, Kansas, Nebraska
By the Numbers
Location
Cause → Event → Consequence
Napoleon Bonaparte had regained Louisiana from Spain in 1800 to rebuild a French colonial empire, but France's failure to suppress the Saint-Domingue revolt and the looming renewal of war with Britain made holding the territory impractical. President Thomas Jefferson, eager to secure navigation rights on the Mississippi River and control of New Orleans, had already directed envoys to negotiate a purchase.
On April 30, 1803, U.S. representatives James Monroe and Robert R. Livingston, negotiating with French Treasury Minister François Barbé-Marbois, agreed to purchase the entire Louisiana territory for fifteen million dollars. Congress subsequently ratified and funded the treaty, overcoming Federalist opposition with the backing of Jefferson and Secretary of State James Madison.
The acquisition extended U.S. sovereignty across the Mississippi River, nominally nearly doubling the country's size and encompassing land that would become fifteen present U.S. states and portions of two Canadian provinces. Western and northern borders were later formalized by the Adams–Onís Treaty of 1819 and the Treaty of 1818, and the purchase laid the foundation for the United States' continental expansion.