There are 18 US Post Offices in Franklin County serving a total of 30,200 residents equating to 1,678 residents per post office. It's estimated that approximately 48,203 packages are handled across the 18 county post offices annually. Franklin County is a county located in the state of Maine, in the United States. As of the 2010 census, the population was 30,768, making it the second-least populous county in Maine. Its county seat is Farmington. The county was established on May 9, 1838 and named for Benjamin Franklin."