Missouri. According to WashU map, the University of Washington (St. Louis) is located in St. Louis, Missouri, USA, and is a private comprehensive research university in the United States. Missouri is a state in the midwest. Founded in August 182 1, it is the 24th state in the United States. This state is nicknamed "Show Me" because local people like to see the truth before they believe it. The name of Missouri comes from the meaning of "canoe" in the native Sioux language of Missouri. The capital of the state is Jefferson, and the postal code is abbreviated as MO.