University of Illinois Urbana‑Champaign

Geographic Region: Counties

IECAM provides a map of Illinois counties for reference purposes. Counties are the primary legal divisions in Illinois.

Source of definition: U.S. Census Bureau, Geography Division. Geographic Terms and Concepts – County or Statistically Equivalent Entity.

There are 102 counties in Illinois. The number of counties has remained stable since the middle of the 19th century.

The county is the principal geographic region for presentation of data on IECAM. All site-based data (e.g., child care), most nonsite-based data (e.g., early intervention), and almost all demographic data (e.g., population) are presented by county.

Counties in Illinois