High Quality Content by WIKIPEDIA articles! High Quality Content by WIKIPEDIA articles! Trousdale County is a county located in the U.S. state of Tennessee. As of 2000, the population was 7,259. In area, it is the smallest county in Tennessee at 114 sq mi (296 km²). Its county seat is Hartsville, with which it shares a consolidated city-county government. The county is named for William Trousdale (1790-1872), Brigadier General in the Mexican War, Governor of Tennessee, 1849-1851, and U.S. Minister to Brazil, 1853-1857.