| | Description: | Marshall County, located in central Illinois, covers an area of 386 square miles and had a 2003 population of 13,039, according to estimates by the U.S. Department of Commerce's Bureau of the Census. Using these figures, Marshall County was the 27th smallest county in Illinois geographically, but 20th smallest in terms of population. Combining these two measures, Marshall County had the 28th smallest population density per square mile among Illinois 102 counties. | |
