County Subdivisions are the primary divisions of counties. (The Census Bureau sometimes uses the term minor civil division instead of county subdivision in cases where the county subdivision is a primary governmental unit.) The township is one type of county subdivision that has elected officials. The precinct is another type of county subdivision that has no elected officials but primarily serves as an election district.
Source of definition:
- U.S. Census Bureau, Geography Division. Geographic Terms and Concepts –County Subdivision
Date of definition: July 2012
Note: In Illinois, three different names are used for county subdivisions:
- township – used in most counties
- precinct – used in Alexander, Calhoun, Edwards, Hardin, Johnson, Massac, Menard, Monroe, Morgan, Perry, Pope, Pulaski, Randolph, Scott, Union, and Wabash Counties
- city – used for Chicago, which is a subdivision of Cook County
Note: IECAM uses the term township to refer to all three of these types of county subdivisions.
Note on searching school district by year: number of townships and yearly changes in townships: In the 2014 data reported on IECAM, based on the Census Bureau’s American Community Survey, there are 1,710 townships (or other county subdivisions) reported for Illinois. County subdivisions periodically change (more so in counties that use precincts) as old subdivisions are combined or divided, as new subdivisions are created, and as county subdivisions undergo boundary changes. Therefore:
- the number of townships (or other county subdivisions) may change from year to year
- township X in one year may not cover the same geographic area as township X the following year
- a township may not have the same name from one year to the next
Note on data availability by township: Almost all site-based data (e.g., child care) and almost all demographic data (e.g., population) are presented by township in IECAM. Non-site-based data (e.g., early intervention) are not presented by township.
Note on searching township by year: When a user searches by year and by township in the basic search, IECAM presents results only for those townships that existed in that year. When a user searches by township and several years in the multi-year search, IECAM presents results for all townships that existed in any of the years selected. If the township did not exist in one of the selected years, an indication such as “N/A” will appear in that particular table cell.
Note: View a list of:
- County subdivisions used in IECAM in 2014
- County subdivisions used in IECAM data for 2009
- County subdivisions used in IECAM data for 2005-2008
For information on changes in county subdivisions across various years, see the Data by Geographic Region by Year page.
Web Resources: Geographic Regions
- IPUMS-USA’s “Composition of PUMAs and Super-PUMAs”
2000 PUMAs and on the composition of the 2000 PUMAs by state
- United States Census Bureau: Geographic Terms and Concepts –
- Illinois Department of Human Services: Division of Human Capital Development (HCD)
- United States Census Bureau: 2010 Census Public Use Microdata Area (PUMA) Reference Maps – Illinois
A list of which counties and/or which parts of counties are associated with which PUMAs, and for maps of the 2010 PUMAs for Illinois