The Illinois Neighborhood Explorer helps you to research any Illinois neighborhood (census block group) and get home values, average household income, owner/renter/ occupancy rates, projected growth rates, boundary maps, comparisons to other communities, and much more.
Illinois State Flower - Illinois Native Violet
The area of Illinois was part of the original territory of the United States, being part of lands ceded by four states to the United States and designated in 1787 as the "Territory northwest of the River Ohio." Illinois Territory was organized on February 3, 1809, from the western part of Indiana Territory, and included all of present-day Illinois, most of Wisconsin, the western part of the Upper Peninsula of Michigan, and northeastern Minnesota.
Although the territory had not yet been legally established, census data for Illinois are available beginning with the 1800 census. The 1810 population is for the entire area of the Illinois Territory, including territory not in the present state. For an explanation of the revision to the 1800 population of Illinois, see Richard L. Forstall, Population of States and Counties of the United States: 1790-1990, Washington, DC: U.S. Government Printing Office, 1996, page 48.
Data for the legally established state of Illinois are available beginning with the 1820 census.
See: Geographic Terms & Concepts
Interactive Map of Illinois Counties | Static Overview Map of Illinois Counties
There are 102 counties in Illinois. All counties are functioning governmental units; each is governed by a board with between 5 and 29 members.
-- Select County --
Adams County
Alexander County
Bond County
Boone County
Brown County
Bureau County
Calhoun County
Carroll County
Cass County
Champaign County
Christian County
Clark County
Clay County
Clinton County
Coles County
Cook County
Crawford County
Cumberland County
De Witt County
DeKalb County
Douglas County
DuPage County
Edgar County
Edwards County
Effingham County
Fayette County
Ford County
Franklin County
Fulton County
Gallatin County
Greene County
Grundy County
Hamilton County
Hancock County
Hardin County
Henderson County
Henry County
Iroquois County
Jackson County
Jasper County
Jefferson County
Jersey County
Jo Daviess County
Johnson County
Kane County
Kankakee County
Kendall County
Knox County
Lake County
LaSalle County
Lawrence County
Lee County
Livingston County
Logan County
Macon County
Macoupin County
Madison County
Marion County
Marshall County
Mason County
Massac County
McDonough County
McHenry County
McLean County
Menard County
Mercer County
Monroe County
Montgomery County
Morgan County
Moultrie County
Ogle County
Peoria County
Perry County
Piatt County
Pike County
Pope County
Pulaski County
Putnam County
Randolph County
Richland County
Rock Island County
Saline County
Sangamon County
Schuyler County
Scott County
Shelby County
St. Clair County
Stark County
Stephenson County
Tazewell County
Union County
Vermilion County
Wabash County
Warren County
Washington County
Wayne County
White County
Whiteside County
Will County
Williamson County
Winnebago County
Woodford County
There are 1,710 county subdivisions in Illinois known as minor civil divisions (MCDs); 85 counties have functioning, but not necessarily active, townships and 17 counties have nonfunctioning election precincts. There are 1,432 townships and 274 election precincts. Chicago city is independent of any MCD and serves as an MCD equivalent in two counties, creating two county subdivisions. There are also two undefined MCDs that cover the Illinois portion of Lake Michigan. Alexander, Calhoun, Edwards, Hardin, Johnson, Massac, Menard, Monroe, Morgan, Perry, Pope, Pulaski, Randolph, Scott, Union, Wabash, and Williamson counties have election precincts. All other counties have townships. The governing body for each township is an elected township supervisor and a board of trustees.
Illinois State Bird - Cardinal
Illinois has 1,367 places, 1,299 incorporated places and 68 census designated places (CDPs). The incorporated places consist of 300 cities, 16 towns, and 983 villages. The minimum population to incorporate as a city is 2,500. For a village the minimum population for incorporation ranges from 200 (in counties with a population less than 150,000) to 2,500. Incorporated places are dependent within county subdivision with the following exceptions:
Independent of any township
Coextensive with a single township
Alton
Belleville
Berwyn
Bloomington
Champaign
Cicero
East St. Louis
Evanston
Freeport
Galesburg
Godfrey
Macomb
Oak Park
Quincy
River Forest
Urbana
Warsaw
Zion
Coextensive with a single precinct
Coextensive with multiple whole precincts
Jacksonville
South Jacksonville
Waterloo
Coextensive with one more precincts in Monroe County, but also has part of one township in St. Clair County
Columbia city
Hecker village
Contain one or more whole precincts and parts of others
Du Quion
Metropolis
Petersburg
Pinckneyville
Alphabetical List of Cities, Towns, CDPs and Other Populated Places A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q, R | S | T | U, V | W, X, Y, Z
Illinois Civil Features : Political Subdivisions, Native Areas, Land Grants, etc. - sorted by Census Class Codes .
There are 9 Metropolitan and 20 Micropolitan Statistical Areas in Illinois. IL Metopolitan & Micropolitan Areas
There are 1,384 ZIP Code tabulation areas (ZCTAs) in Illinois. View Illinois ZIP Codes and ZIP Code Maps .
There are 379 elementary school districts, 104 secondary school districts, and 389 unified school districts in Illinois. View Illinois Public and Private Schools .
Illinois has 19 congressional districts. An interactive map shows the contact information for each Representative as well as the boundaries for each Illinois district. View Map of Illinois Congressional Districts .
There are 59 state senate districts and 118 state house districts in Illinois. There is also one state house district undefined and one state senate district undefined each comprising the portion of Illinois in Lake Michigan.
