There are 14 US Post Offices in Macon County serving a total of 58,017 residents equating to 4,144 residents per post office. It's estimated that approximately 92,602 packages are handled across the 14 county post offices annually. Macon County is a county located in the U.S. state of Illinois. According to the 2010 census, it had a population of 110,768. Its county seat is Decatur. Macon County comprises the Decatur, IL Metropolitan Statistical Area."