There are 5 US Post Offices in Henderson County serving a total of 24,715 residents equating to 4,943 residents per post office. It's estimated that approximately 39,448 packages are handled across the 5 county post offices annually. Henderson County is a county located in the U.S. state of Tennessee. As of the 2010 census, the population was 27,769. Its county seat is Lexington. The county was founded in 1821 and named for James Henderson, a soldier in the War of 1812."