There are 10 US Post Offices in Barry County serving a total of 38,534 residents equating to 3,853 residents per post office. It's estimated that approximately 61,505 packages are handled across the 10 county post offices annually. Barry County is a county located in the southwest portion of the U.S. state of Missouri. As of the 2010 Census, the population was 35,597. Its county seat is Cassville. The county was organized in 1835 and named after William Taylor Barry, a U.S. Postmaster General from Kentucky.