Home Milestones 1801-1829 Louisiana Purchase, 1803 Milestones: 1801–1829 NOTE TO READERS “Milestones in the History of U.S. Foreign Relations” has been retired and is no longer maintained. For more information, please see the full notice. The Louisiana Purchase encompassed 530,000,000 acres of territory in North America that the United States purchased from France in 1803 for $15 million. The Louisiana Purchase As the United States spread across the Appalachians, the Mississippi River became an increasingly important conduit for the produce of America’s West (which at that time referred to the land between the Appalachians and the Mississippi). Since 1762, Spain had owned the territory of Louisiana, which included 828,000 square miles. The territory made up all or part of fifteen modern U.S. states between the Mississippi River and the Rocky Mountains. The Pinckney treaty of 1795 had resolved friction between Spain and the United States over the right to navigate the Mississippi and th...
