There are 13 US Post Offices in Clinton County serving a total of 48,222 residents equating to 3,709 residents per post office. It's estimated that approximately 76,968 packages are handled across the 13 county post offices annually. Clinton County is a county located in the U.S. state of Iowa. As of the 2010 census, the population was 49,116. Its county seat is Clinton. Its name is in honor of the seventh Governor of New York State, DeWitt Clinton. Clinton County comprises the Clinton, IA Micropolitan Statistical Area, which is also included in the Davenport-Moline, IA-IL Combined Statistical Area."