There are 3 US Post Offices in Madison County serving a total of 13,125 residents equating to 4,375 residents per post office. It's estimated that approximately 20,949 packages are handled across the 3 county post offices annually. Madison County is a county located in the U.S. state of Texas. As of the 2010 census, its population was 13,664. Its seat is Madisonville. The county was created in 1853 and organized the next year. It is named for James Madison, the fourth president of the United States."