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Census 2020: Impact on Illinois

The Census 2020 Guide brings together resources about why the Census is important, key information about the Census, and where to find additional information.

Illinois Complete Count Commission

For information about Illinois and the 2020 Census, see U.S. Census QuickFacts Illinois.

Census 2020 Make Sure Illinois Counts

Why a complete count is important to Illinois

According to the Illinois Complete Count Commission, Illinois was undercounted in the 2010 Census with only 76% participation rate.  The ramifications for undercounting in Illinois in the 2020 Census include:

  • Loss of at least one seat in the House of Representatives.
  • Loss of at least one Electoral College vote.
  • Forfeiture of billions of dollars of federal assistance for programs that aid children, veterans, senior citizens, middle and low income families, schools, healthcare facilities, and infrastructure.

Illinois Complete Count Commission, Interim Report to the Illinois General Assembly, November, 2018.

Results of 2020 Census and Impact on Illinois

According to the the 2020 Census count, Illinois lost population since the 2010 Census.  As a result, Illinois will lose one Congressional seat in the U.S. House of Representatives and one Electoral College vote.  It likely will lose substantial federal aid as well.

2020 Census Apportionment Results, U.S. Census Bureau
U.S. Census QuickFacts Illinois, U.S. Census Bureau
Illinois Sees Second Largest Population Loss of U.S. States, Chicago Metropolitan Agency for Planning.

Further resources on Illinois' loss of population:

Where Illinois is Losing Population, Chicago Magazine, February 4, 2021.
Five Charts That Show Who's Leaving Illinois and Why, WBEZ Chicago, January 8, 2020.

Census Total Response Rates by State, U.S. Census Bureau.