Geographic Region: Townships
About the data
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
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, a subdivision of Cook County
IECAM uses the term township to refer to all three of these types of county subdivisions.
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, and
- a township may not have the same name from one year to the next.
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.
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 multiyear 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.
For information on changes in county subdivisions across various years, see the Data Availability page.