There are 19 US Post Offices in Madison County serving a total of 247,872 residents equating to 13,046 residents per post office. It's estimated that approximately 395,631 packages are handled across the 19 county post offices annually. Madison County is a county of the U.S. state of Alabama. As of the 2010 Census, the population was 334,811. Its county seat is Huntsville. The county is named in honor of James Madison, fourth President of the United States of America and the first President to visit the state of Alabama. Madison County covers parts of the former Decatur County. Madison County is included in the Huntsville, AL Metropolitan Statistical Area."