Mapping Illinois’ Hard to Count (HTC) Communities for a Fair and Accurate 2020 Census
Welcome to the 2020 Census Illinois Hard to Count Index map site.

An accurate count of Illinois' population is essential to ensure that Illinois receives the funding it needs to adequately and effectively care for its residents and to provide critical services and programs. The State of Illinois’ Census Office is supporting a statewide census outreach and education effort to reach the highest self-response rate possible. The State's strategies will prioritize HTC communities, and encourage all Illinois residents to participate in the 2020 Census.

This site has three maps, which can assist in identifying HTC geographies. To see detailed information about an area, hover your mouse over the map. You can zoom in to a specific area to view data on hard-to-count populations or non-responsive areas.

Index Map: This map highlights census tracts that are in the top 30% of those with the highest index scores, and therefore deemed hardest to count. Each tract is classified by color, with darker colors indicating areas that are more difficult to count. By hovering over a tract, you will see data on the 18 variables (variable, percentage of the tract, and population) that were calculated in the Index. (Click on the Hard-to-Count Variables list at the top of this page for more details.) Race and ethnicity information is displayed, but not included in the Index.

Census 2010 Response Rates: This map shows the areas where there were high levels of non-response to the 2010 Census. There may be similar patterns in 2020. The non-response was to initial mailings of the form requiring the Census Bureau to visit these areas to finish completing the Census. The goal is to obtain as high of a response as possible.

ACS 2017 Response Rates: This map is similar to the 2010 Census Response Rates map. The American Community Survey (ACS) is conducted all year round, so the information is more current on those areas that are not responding to the Census Bureau, as neighborhoods could have changed since 2010.

Low Mail Access Areas: The "TEA" map, or Type of Enumeration Area, as it is called by the Census Bureau, provides additional information about areas throughout Illinois known to only have Rural Routes or PO Boxes, for example. The Census Bureau requires a physical address to assign data to. Without physical addresses, it is more difficult to collect data in those areas and may require more manual effort.