There are 6 US Post Offices in Lee County serving a total of 9,898 residents equating to 1,650 residents per post office. It's estimated that approximately 15,798 packages are handled across the 6 county post offices annually. Lee County is a county located in the U.S. state of Arkansas. As of the 2010 census, the population was 10,424. The county seat is Marianna. Lee County is Arkansas's 72nd county, formed alongside St. Francis and Phillips counties on April 17, 1873, and named for Confederate General Robert E. Lee."