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Statewide Population Change Map [ PDF | JPG ]

Custom Tables [ PDF | JPG ]

To access data from multiple geographies within the state, such as census blocks, tracts, voting districts, cities, counties and school districts, visit American Factfinder: http://factfinder2.census.gov.

From the U.S. Bureau:

The official 2010 Census Redistricting Data Summary File can be used to redraw federal, state and local legislative districts under Public Law 94-171. The census data are used by state officials to realign congressional and state legislative districts in their states, taking into account population shifts since the 2000 Census.

Data for Illinois show that the five most populous incorporated places and their 2010 Census counts are Chicago, 2,695,598; Aurora, 197,899; Rockford, 152,871; Joliet, 147,433; and Naperville, 141,853. Chicago decreased by 6.9 percent since the 2000 Census. Aurora grew by 38.4 percent, Rockford grew by 1.8 percent, Joliet grew by 38.8 percent, and Naperville grew by 10.5 percent.

The largest county is Cook with a population of 5,194,675. Its population decreased by 3.4 percent since 2000. The other counties in the top five include DuPage, with a population of 916,924 (increase of 1.4 percent); Lake, 703,462 (increase of 9.2 percent); Will, 677,560 (increase of 34.9 percent); and Kane, 515,269 (increase of 27.5 percent).

The redistricting file consists of five detailed tables: the first shows the population by race, including six single race groups and 57 multiple race groups (63 total race categories); the second shows the Hispanic or Latino population as well as the non-Hispanic or Latino population cross-tabulated by the 63 race categories. These tabulations are repeated in the third and fourth tables for the population 18 years and over and are for the resident population of the United States. The fifth table provides counts of housing units and their occupancy status.

These five detailed tables are available to the public online via FTP download at http://www2.census.gov/census_2010/01-Redistricting_File--PL_94-171/ and will be available within 24 hours at http://factfinder2.census.gov. (Access 2003 or Access 2007 shells or SAS scripts are provided to assist with importing and accessing the summary file data from the FTP site. These shells and scripts can be found at http://www.census.gov/rdo/tech_tips. This Web page also contains special instructions for linking data downloaded from FactFinder and/or the FTP site with the Census Bureau's geographic products.)

By April 1, all 50 states, the District of Columbia and Puerto Rico will receive these data for the following areas: state, congressional districts (for 111th Congress), counties, minor civil divisions, state legislative districts, places, school districts, census tracts, block groups and blocks, and if applicable, American Indian and Alaska Native areas and Hawaiian home lands. In addition, data are available for the 46 states that voluntarily provided voting districts to the Census Bureau's Redistricting Data Program. Unique geographies for the Commonwealth of Puerto Rico are also available.

Race and Hispanic Origin Data

The Census Bureau collects race and Hispanic origin information following the U.S. Office of Management and Budget's (OMB) standards for collecting and tabulating data on race and ethnicity. In October 1997, the OMB issued the current standards, which identify five race groups: white, black or African-American, American Indian or Alaska Native, Asian, and Native Hawaiian or Other Pacific Islander. The Census Bureau also utilized a sixth category -- “some other race.” Respondents who reported only one race are shown in these six groups.

Individuals were first presented with the option to self-identify with more than one race in the 2000 Census, and this continued in the 2010 Census. People who identify with more than one race may choose to provide multiple races in response to the race question. The 2010 Census results provide new data on the size and makeup of the nation's multiracial population.

Respondents who reported more than one of the six race groups are included in the "two or more races" population. There are 57 possible combinations of the six race groups.

The Census Bureau included the “some other race” category for responses that could not be classified in any of the other race categories on the questionnaire. In the 2000 Census, the vast majority of people who reported only as “some other race” were of Hispanic or Latino origin. Data on Hispanics or Latinos, who may be of any race, were obtained from a separate question on ethnicity.

How to Find Assistance

Additional information about the redistricting data program, including news releases for other states, can be found online at http://2010.census.gov/news/press-kits/redistricting.html. More information on the redistricting data program is also available at http://www.census.gov/rdo/data.

For further information about Illinois' 2010 Census redistricting data, contact:

  • Census Redistricting Data Office, U.S. Census Bureau, 301-763-4039; e-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it ;
  • Census Bureau Regional Office, Chicago, 630-288-9200; e-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it
  • State Data Centers http://www.census.gov/sdc/network.html