Founded in 1786, Knoxville is the third-largest city in the U.S. state of Tennessee, behind Memphis and Nashville, and is the county seat of Knox County.It is also the largest city in East Tennessee. As of the 2000 United States Census, Knoxville had a total population of 173,890. Knoxville's economy is largely fueled by the regional location of the main campus of the University of Tennessee, the Oak Ridge National Laboratory and other Department of Energy facilities in nearby Oak Ridge, the National Transportation Research Center, and the Tennessee Valley Authority. Because of its central location in the eastern half of the United States and proximity to two major Interstate highways, many warehousing and distribution companies operate in and around Knoxville.