There are 8 US Post Offices in Madison County serving a total of 15,060 residents equating to 1,883 residents per post office. It's estimated that approximately 24,037 packages are handled across the 8 county post offices annually. Madison County is a county located in the U.S. state of Arkansas. As of the 2010 census, the population was 15,717. The county seat is Huntsville. The county was formed on September 30, 1836, and named for James Madison, fourth President of the United States. Madison County is part of the Fayetteville\u2013Springdale\u2013Rogers, AR-MO Metropolitan Statistical Area."