It comprises 114 counties and one independent city. Missouri's capital is Jefferson City. The four largest urban areas are, in descending order, St. Louis, Kansas City, Springfield, and Columbia. Missouri was originally acquired from France as part of the Louisiana Purchase and became defined as the Missouri Territory. Part of the Missouri Territory was admitted into the union as the 24th state in 1821.

Missouri mirrors demographic, economic and political makeup of the nation with a mixture of urban and rural culture. It has long been considered a political bellwether state. With the exception of the 1956 and 2008 presidential elections, Missouri's election results have accurately predicted the next President of the United States since 1904. It has both Midwestern and Southern cultural influences, reflecting its history as a border state. It is also a transition between the eastern and western United States, as St. Louis is often called the "western-most eastern city" and Kansas City the "eastern-most western city." Missouri's geography is highly varied. The northern part of the state lies in dissected till plains while the southern part lies in the Ozark Mountains, with the Missouri River dividing the two. The confluence of the Mississippi and Missouri rivers is located near St. Louis.