Madison County, Illinois is part of the St. Louis metropolitan statistical area and home to more than 250,000 people.
The ancient Native American city of Cahokia once thrived there. Over a millennia ago, it may have been one of the biggest cities in the world. Today the Cahokia Mounds are a World Heritage Site.
In 2016, Donald Trump carried the county by the largest margin of any presidential candidate since Richard Nixon in 1972.