What was the 1803 land deal in which the United States bought Louisiana from France called?

The 1803 land deal in which the United States bought Louisiana from France was called the Louisiana Purchase.

The treaty was signed in Paris on April 30, 1803, by Robert Livingston and James Monroe for the United States and François Barbé-Marbois for France. The United States agreed to pay $15 million for the vast territory, which stretched from the Mississippi River toward the Rocky Mountains and from the Gulf of Mexico northward.

President Thomas Jefferson had originally instructed the American negotiators to seek New Orleans and nearby land, because control of the Mississippi River was vital to western farmers and commerce. Napoleon’s government unexpectedly offered the entire Louisiana Territory, and the American negotiators accepted.

The purchase nearly doubled the nominal size of the United States. It was not the same as the Alaska Purchase of 1867 or the Gadsden Purchase of 1854. The territory’s boundaries and Native sovereignty were complex, and the federal government later organized the land into multiple territories and states.