What was the 1803 U.S. purchase from France that doubled the nation's territory?

The Louisiana Purchase was the 1803 U.S. purchase from France that doubled the nation's territory. The United States acquired roughly 530 million acres for $15 million, or about three cents per acre at the time.

President Thomas Jefferson authorized the agreement after France offered to sell the entire Louisiana territory. The land stretched from the Mississippi River to the Rocky Mountains and from the Gulf of Mexico toward the Canadian border, although its exact boundaries were not immediately clear.

The treaty was signed in Paris on April 30, 1803, and the United States formally took possession later that year. The purchase secured the Mississippi River and the port of New Orleans for American commerce. It also created major diplomatic, legal, and ethical questions involving Indigenous nations and slavery as the country expanded westward.