There are 12 US Post Offices in Northampton County serving a total of 11,620 residents equating to 968 residents per post office. It's estimated that approximately 18,547 packages are handled across the 12 county post offices annually. Northampton County is a county located in the Commonwealth of Virginia. As of the 2010 census, the population was 12,389. Its county seat is Eastville. Northampton and Accomack Counties comprise the Eastern Shore of Virginia. The county is the center of the late Eocene meteor strike that resulted in the Chesapeake Bay impact crater. The Northampton County Courthouse Historical District is part of the Eastville Historical District at the county seat."