In 1803, President Thomas Jefferson completed a treaty with the French government to purchase a large section of land in North America. This land is now known as the LOUISIANA 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 its independence from Great Britain 20 years earlier. The territory gained in the LOUISIANA PURCHASE was the largest in U.S. history, totaling 828,000 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