What significant acquisition, purchased by Thomas Jefferson, doubled the size of the U.S.?

The Louisiana Purchase is indeed the acquisition that significantly expanded the size of the United States, effectively doubling it. In 1803, Thomas Jefferson authorized the purchase of approximately 827,000 square miles of territory from France, which included land that would eventually become 15 states. This strategic move not only provided a wealth of agricultural land but also controlled key trade routes, such as the Mississippi River. The acquisition was pivotal in shaping the future of the nation, facilitating westward expansion and exploration, notably exemplified by the Lewis and Clark expedition. This monumental transaction set a precedent for future territorial expansion and was key in establishing the U.S. as a major player on the North American continent.