There are 9 US Post Offices in Lincoln County serving a total of 50,385 residents equating to 5,598 residents per post office. It's estimated that approximately 80,420 packages are handled across the 9 county post offices annually. Lincoln County is a county located in the eastern portion of the U.S. state of Missouri. As of the 2010 census, the population was 52,566. Its county seat is Troy. The county was founded December 14, 1818, and named for Major General Benjamin Lincoln of the American Revolutionary War. Lincoln County is part of the St. Louis, MO-IL Metropolitan Statistical Area.