Answer :
Final answer:
President Jefferson made the significant Louisiana Purchase in 1803, effectively doubling the size of the United States.
Explanation:
The significant land acquisition made by President Jefferson was the Louisiana Purchase. In 1803, the United States purchased 828,000,000 acres of land from France, effectively doubling the country's size. The acquisition was vital for westward expansion and securing access to the Mississippi River.
Learn more about Louisiana Purchase here:
https://brainly.com/question/29760168
