There are 4 US Post Offices in Barbour County serving a total of 26,188 residents equating to 6,547 residents per post office. It's estimated that approximately 41,799 packages are handled across the 4 county post offices annually. Barbour County is a county in the U.S. state of Alabama. As of the 2010 census, the population was 27,457. Its county seat is Clayton. Its name is in honor of James Barbour, who served as Governor of Virginia.