The United States paid $15 million for the Louisiana Purchase from France in 1803.
The agreement transferred a vast territory centered on the Mississippi River basin. The land eventually contributed to all or parts of several modern states, although its exact boundaries and the extent of French control were complicated. The purchase more than doubled the size of the United States.
President Thomas Jefferson had initially authorized negotiators Robert Livingston and James Monroe to seek New Orleans and nearby territory. Napoleon Bonaparte’s government unexpectedly offered the entire Louisiana territory, partly because France faced renewed conflict with Britain and had lost its ability to sustain a North American empire.
The treaty was signed in Paris on April 30, 1803, and announced in the United States on July 4. The price is often remembered as a bargain, but the acquisition also raised constitutional questions and intensified later disputes over slavery and Indigenous sovereignty.