Knoxville is a city in the U.S. state of Tennessee, and the county seat of Knox County. The city had an estimated population of 185,291 in 2015 and a population of 178,874 as of the 2010 census, making it the state's third largest city after Memphis and Nashville. Knoxville is the principal city of the Knoxville Metropolitan Statistical Area, which, in 2013, had an estimated population of 852,715. The KMSA is, in turn, the central component of the Knoxville-Sevierville-La Follette Combined Statistical Area, which, in 2013, had a population of 1,096,961.First settled in 1786, Knoxville was the first capital of Tennessee. The city struggled with geographic isolation throughout the early 19th century. The arrival of the railroad in 1855 led to an economic boom. During the Civil War, the city was bitterly divided over the secession issue, and was occupied alternately by both Confederate and Union armies. Following the war, Knoxville grew rapidly as a major wholesaling and manufacturing center. The city's economy stagnated after the 1920s as the manufacturing sector collapsed, the downtown area declined and city leaders became entrenched in highly partisan political fights. Hosting the 1982 World's Fair helped reinvigorate the city, and revitalization initiatives by city leaders and private developers have had major successes in spurring growth in the city, especially the downtown area.Knoxville is the home of the flagship campus of the University of Tennessee, whose sports teams, called the "Volunteers" or "Vols," are extremely popular in the surrounding area. Knoxville is also home to the headquarters of the Tennessee Valley Authority, the Tennessee Supreme Court's courthouse for East Tennessee and the corporate headquarters of several national and regional companies. As one of the largest cities in the Appalachian region, Knoxville has positioned itself in recent years as a repository of Appalachian culture and is one of the gateways to the Great Smoky Mountains National Park.