The history of Missouri begins with settlement of the region by indigenous people during the Paleo-Indian period beginning in about 12,000 BC. Subsequent periods of native life emerged until the 17th century. New France set up small settlements, and in 1803 Napoleonic France sold the area to the U.S. as part of the Louisiana Purchase. Statehood for Missouri came following a compromise in 1820 that allowed slavery. Settlement was rapid after 1820, aided by a network of rivers navigable by steamboats, centered in the dominant city St. Louis. It attracted European immigrants, especially Germans; the business community had a large Yankee element as well. The Civil War saw numerous small battles and control by the Union. After the war, its economy became more diverse, and railroads, centered in