Louisiana Purchase

Credit: William Morris · CC BY-SA 4.0
The Louisiana Purchase was a huge land deal in 1803 between the United States and France. The United States bought 828,000 square miles of land west of the Mississippi River. The deal doubled the size of the country overnight. President Thomas Jefferson made the purchase. France was led by Napoleon Bonaparte at the time.
The land stretched from the Mississippi River all the way to the Rocky Mountains. It also reached from the Gulf of Mexico north to Canada. All or part of 15 modern states were carved out of this land. These include Louisiana, Arkansas, Missouri, Iowa, Kansas, Nebraska, Oklahoma, and the Dakotas. The territory was about four times the size of France itself.
France had only just gotten the land back from Spain in 1800. Napoleon hoped to build a French empire in North America. But things went wrong. A slave revolt in Haiti, a French colony in the Caribbean, defeated his army. Napoleon also needed money for a coming war with Britain. He decided to sell the whole territory.
Jefferson had only sent his men to buy the city of New Orleans. New Orleans sat where the Mississippi River meets the sea. American farmers needed it to ship their crops. When France offered the entire territory for $15 million, the American buyers said yes on the spot. That comes to about 3 cents per acre.
Jefferson worried the deal might not be legal. The Constitution did not say the president could buy land from another country. But he decided the chance was too good to miss. The Senate approved the treaty in October 1803. The American flag was raised over New Orleans that December.
The purchase changed the country in big ways. Jefferson sent Meriwether Lewis and William Clark to explore the new land. Their journey lasted from 1804 to 1806. They mapped rivers, met Native nations, and reached the Pacific Ocean. Their guide for part of the trip was a young Shoshone woman named Sacagawea.
The deal had a darker side too. The land was not empty. Many Native American nations had lived there for thousands of years, including the Osage, Lakota, Pawnee, and Comanche. France sold the land without asking them. In the years that followed, the United States pushed these nations off the land through wars and forced removals.
The Louisiana Purchase is often called one of the best deals in American history. For about $15 million, the United States gained land that became some of its richest farms, biggest rivers, and tallest mountains. But the deal also set the stage for many hard years to come.
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Last updated 2026-04-26
