There are 14 US Post Offices in Columbus County serving a total of 58,348 residents equating to 4,168 residents per post office. It's estimated that approximately 93,130 packages are handled across the 14 county post offices annually. Columbus County is a county located in the U.S. state of North Carolina. As of the 2010 census, the population was 58,098. Its county seat is Whiteville."