| | Description: | Williamson County, located in southern Illinois, covers an area of 424 square miles and had a 2003 population of 62,448, according to estimates by the U.S. Department of Commerce's Bureau of the Census. Using these figures, Williamson County was the 68th largest county in Illinois geographically, but 23rd largest in terms of population. Combining these two measures, Williamson County had the 20th highest population density per square mile among Illinois 102 counties. | |
