How did the united states acquire the louisiana purchase?

From france

In exchange, the United States acquired the vast domain of Louisiana Territory, some 828,000 square miles of land. The treaty was dated April 30 and signed on May 2. In October, the U.S. Senate ratified the purchase, and in December 1803 France transferred authority over the region to the United States.

A, i have to keep writing because the website doesn't allow me to post one lettered responses