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 population of 5,987,580, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. Missouri mirrors the demographic, economic and political makeup of the nation (in general) with a mix of urban and rural culture.