Answer:
He purchased it from France
Explanation:
Jefferson's envoys in Paris, without awaiting any direction from their President (which would have taken two months), accepted the deal and on April 30, 1803, signed the Louisiana Purchase Treaty. In mid-April 1803, shortly before Monroe's arrival, the French asked a surprised Livingston if the United States was interested in purchasing all of Louisiana Territory. ... In October, the U.S. Senate ratified the purchase, and in December 1803 France transferred authority over the region to the United States.