President Thomas Jefferson complete a treaty with the French government to purchase a large section of land in North America. this land is now know as the Lousiana purchase. The purchase was important to the future of the U.S. It was the first major expansion of the U.S. since it had won is independence from Great Britain 20 year earlier. The territory gained in the Louisiana Purchase was the largest in U.S. history, totaling 823,000 squares miles, about 23% of the current U.S. land area. The Louisiana Purchase also secured the U.S.'s right to passage along the Mississippi River and allowed access to the important port of New Orleans.
1903 map of the Louisiana purchase from the u.s. Department of interior.
Treaty transferring the Louisiana purchase from France to the U.S.