There are 31 US Post Offices in Shelby County serving a total of 752,925 residents equating to 24,288 residents per post office. It's estimated that approximately 1,201,752 packages are handled across the 31 county post offices annually. Shelby County is a county located in the U.S. state of Tennessee. As of the 2010 census, the population was 927,644. It is the state's largest county both in terms of population and geographic area. Its county seat is Memphis, the most populous city in Tennessee. The county was named for Governor Isaac Shelby (1750\u20131826) of Kentucky. Shelby County is part of the Memphis, TN-MS-AR Metropolitan Statistical Area. It is bordered on the west by the Mississippi River. Within the Mississippi Delta, the county developed as a center of cotton plantations in the antebellum era, and cotton continued as an important commodity crop well into the 20th century. The economy has become more diversified."