Columbia is the fifth-largest city in the U.S. state of Missouri and the largest city in Mid-Missouri. With an estimated population of 100,733 in 2008, it is the principal municipality of the Columbia Metropolitan Area, a region of 164,283 residents. The city serves as the county seat of Boone County and as the location of the University of Missouri. The college town is politically liberal and is known by the nicknames "The Athens of Missouri," "College Town USA," and "CoMO. " Over half of Columbians possesses a bachelor's degree and over a quarter hold graduate degrees, making it the thirteenth most highly educated municipality in the United States. Columbia was settled in Pre-Columbian times by the mound-building Mississippian culture of Native Americans. In 1818, a group of settlers incorporated under the Smithton Land Company purchased over 2,000 acres (8 km²) and established the village of Smithton near present-day downtown Columbia. In 1821, the settlers moved and re-named the settlement Columbia—a poetic name for the United States. The founding of the University of Missouri in 1839 established the city as a center of education and research. By 1851, two other institutions of higher education, Stephens College and Columbia College were established within the city. Located among small tributary valleys of the Missouri River, Columbia is roughly equidistant from St. Louis and Kansas City. Greater St. Louis is 70 miles (110 km) to the East, and the Kansas City Metropolitan Area is 100 miles (160 km) to the West. Today, Columbia has a highly diversified economy, and is often ranked high for its business atmosphere. Never a strong center of industry and manufacturing, the city's economic base relies on the education, medical, technology and insurance industries. Studies consistently rank Columbia as a top city in which to live for educational facilities, health care, technological savvy, economic growth, cultural opportunities and cost of living. The city has been ranked as high as the second-best place to live in the United States by Money Magazine's annual list and is regularly in the top 100. Residents of Columbia are usually described as "Columbians."