A state of the central United States. It was admitted as the 24th state in 1821. Under Spanish control from 1762 to 1800, the area passed to the United States through the Louisiana Purchase of 1803. Organized as a territory in 1812, Missouri's application for admission as a slaveholding state in 1817 sparked a bitter controversy over the question of extending slavery into new territories. The Missouri Compromise of 1820 provided for the admission of Maine as a free state and Missouri as a slave state in the following year. Jefferson City is the capital and St. Louis the largest city.