| | Description: | Madison County, located in southwestern Illinois, covers an area of 725 square miles and had a 2003 population of 261,689, according to estimates by the U.S. Department of Commerce's Bureau of the Census. Using these figures, Madison County was the 20th largest county in Illinois geographically, but 8th largest in terms of population. Combining these two measures, Madison County had the 9th highest population density per square mile among Illinois 102 counties. | |
