There are 2 US Post Offices in Sheridan County serving a total of 2,206 residents equating to 1,103 residents per post office. It's estimated that approximately 3,521 packages are handled across the 2 county post offices annually. Sheridan County (standard abbreviation: SD) is a county located in the U.S. state of Kansas. As of the 2010 census, the county population was 2,556. Its county seat is Hoxie. The county was named in honor of Phillip H. Sheridan, a general of the American Civil War era."