The "Show Me" state, located in the Midwest, is shaped by the Mississippi River along the eastern border and the Missouri River which flows across the state into the Mississippi near St. Louis, the largest city. Originally inhabited by the Osage and Missouri peoples, the area became part of the United States in 1803 as part of the Louisiana Purchase. Missouri's colorful history continues through the Missouri Compromise of 1821, by which it was admitted as a slave state; and its role as the starting point for wagon trains traveling west. Today, Missouri is home to the major metropolitan centers of Kansas City and St. Louis, and a major center of aerospace, manufacturing, mining, and other industries.