| | Description: | Warren County, located in northern Illinois, covers an area of 542 square miles and had a 2003 population of 18,246, according to estimates by the U.S. Department of Commerce's Bureau of the Census. Using these figures, Warren County was the 47th largest county in Illinois geographically, but 62nd largest in terms of population. Combining these two measures, Warren County had the 27th lowest population density per square mile among Illinois 102 counties. | |
