| | Description: | Massac County, located in southern Illinois, covers an area of 239 square miles and had a 2003 population of 15,138, according to estimates by the U.S. Department of Commerce's Bureau of the Census. Using these figures, Massac County was the 7th smallest county in Illinois geographically, but 76th largest in terms of population. Combining these two measures, Massac County had the 40th highest population density per square mile among Illinois 102 counties. | |
