There are 42 US Post Offices in York County serving a total of 400,246 residents equating to 9,530 residents per post office. It's estimated that approximately 638,837 packages are handled across the 42 county post offices annually. York County is a county in the U.S. state of Pennsylvania. As of the 2010 census, the population was 434,972. Its county seat is York. The county was created on August 19, 1749, from part of Lancaster County and named either for the Duke of York, an early patron of the Penn family, or for the city and shire of York in England. York County comprises the York-Hanover, PA Metropolitan Statistical Area, which is also included in the Harrisburg-York-Lebanon, PA Combined Statistical Area. It is in the Susquehanna Valley, a large fertile agricultural region in South Central Pennsylvania. Based on the Articles of Confederation having been adopted in York by the Second Continental Congress on November 15, 1777, the local government and business community began referring to York in the 1960s as the first capital of the United States of America. The designation has been debated by historians ever since. Congress considered York, and the borough of Wrightsville, on the eastern side of York County along the Susquehanna River, as a permanent capital of the United States before Washington, D.C., was selected."