There are 25 US Post Offices in Davidson County serving a total of 605,581 residents equating to 24,223 residents per post office. It's estimated that approximately 966,575 packages are handled across the 25 county post offices annually. Davidson County is a county located in the U.S. state of Tennessee. As of the 2010 census, the population was 626,681, making it the second-most populous county in Tennessee. Its county seat is Nashville, the state capitol. In 1963, the City of Nashville and the Davidson County government merged, so the county government is now known as the \"Metropolitan Government of Nashville and Davidson County,\" or \"Metro Nashville\" for short. Davidson County has the largest population in the 13-county Nashville-Davidson\u2013Murfreesboro\u2013Franklin Metropolitan Statistical Area. Nashville has always been the region's center of commerce, industry, transportation, and culture, but it did not become the capital of Tennessee until 1827 and did not gain permanent capital status until 1843."