Missouri (abbreviated MO) is a U.S. state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2009 estimated population of 5,987,580, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It comprises 114 counties and one independent city. Missouri's capital is Jefferson City. The four largest urban areas are St. Louis, Kansas City, Springfield, and Columbia.