ILLINOIS
POPULATION DENSITY
People per square mile, 2010: 231.1
People per square mile, 2020: 230.8
HISTORIC & PROJECTED GROWTH 1790 TO 2040
Year |
Population |
1790 |
0 |
1800 |
0 |
1810 |
12,282 |
1820 |
55,211 |
1830 |
157,445 |
1840 |
476,173 |
1850 |
851,470 |
1860 |
1,711,951 |
1870 |
2,539,891 |
1880 |
3,077,871 |
1890 |
3,826,352 |
1900 |
4,821,550 |
1910 |
5,638,591 |
1920 |
6,485,280 |
1930 |
7,630,654 |
1940 |
7,897,241 |
1950 |
8,712,176 |
1960 |
10,081,158 |
1970 |
11,110,285 |
1980 |
11,427,409 |
1990 |
11,430,602 |
2000 |
12,419,293 |
2010 |
12,830,632 |
2020 |
12,812,508 |
2030 |
12,709,901 |
2040 |
12,397,564 |
SOURCE: U.S. Bureau of the Census & Weldon Cooper Center, Demographics Research Group
(The Census Bureau and Weldon Cooper Center have not yet provided updated State projections to reflect 2020 census numbers.)
Population by County
SOURCE: U.S. Bureau of the Census
Illinois Population News Articles
Villanueva fights to advance environmental justice protections in Illinois – Mar 12, 2026
Illinois' Fastest-Growing Cities In 2026, According To Data – Feb 24, 2026
Could a New Illinois Bill Be a Blueprint for Curbing Data Centers’ Climate Impacts? – Feb 19, 2026
Illinois keeps California truck emission rules on life support – Mar 12, 2026
Krishnamoorthi Warns Trump EPA Climate Rollback Threatens Illinois Families’ Health, Raises Costs – Mar 12, 2026
Illinois Passes Comprehensive Immigration Enforcement Protections - Nov 12, 2025
Illinois fully lifts decades-long nuclear moratorium in an important step toward securing clean, reliable, affordable grid – Oct 31, 2025
Wetlands Help Remedy Agricultural Pollution. Some Illinois Farmers Are Installing New Ones. – Oct 23, 2025
Pensions make homeownership unaffordable in Illinois – Oct 23, 2025
Illinois Wants Climate Education in Schools. Now Teachers Need to Figure Out How to Make It Happen. – Oct 20, 2025
Defining clean transportation standards for Illinois – Oct 15, 2025
IL beaches pose danger from bacteria presence – July 10, 2025
How Trump's megabill affects Illinois' environment – July 9, 2025
WATCH: Census data: IL losing 18 and under at faster rate than NY, CA – June 26, 2025
Are fireflies going extinct? What to know about ‘lightning bugs' in Illinois – June 18, 2025
Experts say EPA plan to roll back limits on power plant emissions will harm Chicago air quality – June 16, 2025
Illinois projected to spend $2.5B on migrants by end of 2025, report claims – June 16, 2025
Homelessness increases dramatically in Illinois – Dec 30. 2024
Illinois awarded $20M to begin transition to electric buses – Dec 27, 2024
Illinois reports population growth, buoyed by 112K international migrants – Dec 19, 2024
Illinois EPA Allocates $1 Million for Wastewater Planning Grants to Aid Small Communities – Dec 10, 2024
Students in Illinois get paid to learn skills for jobs in energy efficiency – Dec 10, 2024
Illinois' population increases from last year, ending decade of decline = Dec 10, 2024
Illinois city plans to source its future drinking water from Lake Michigan – Sept 30, 2024
IL bee population stunted by pesticides – Sept 27, 2024
Illinois to ban fluorescent lighting in 2026 – Sept 18, 2024
Chicago to close three shelters by end of October as migrant arrivals fall – Sept 12, 2024
Monarch butterfly numbers have dropped this summer in Illinois, experts say – Sept 8, 2024
Climate change to be required Illinois teaching, thanks to two Naperville students – Sept 6, 2024
11.9% of Illinois Residents Are Experiencing Drought Conditions in 2024 – Sept 4, 2024
Residents of Illinois town evacuate as officials warn of ‘imminent’ dam failure – July 16, 2024
Undocumented immigrants now eligible for standard Illinois driver's licenses with "federal limits" – July 1, 2024
IRS: Illinois loses $10 billion in income from 87,000 people moving out – June 28th, 2024
Most new gas, diesel vehicle sales would be banned in Illinois by 2035 under proposal – June 27, 2024
Illinois is home to 2 of the Dirtiest Cities in America – June 26, 2024
Chicago-area severe weather prompts warnings from climate experts, calls to reduce water use – June 25, 2024
Goodbye, snowy Illinois winters? New climate report offers dry projections – November 20, 2023
Illinois earmarks $160 million to keep migrants warm in Chicago as winter approaches – November 17, 2023
Illinois takes major step toward lowering emissions, thanks to Ventura - November 16, 2023
The 8 Biggest Cities Located on the Shores of Lake Michigan – November 8, 2023
Report Examines Unequal Effects of Climate Change on Lake County Communities – October 26, 2023
Illinois EPA Invites 5th & 6th Grade Student Writers and Artists to Compete in Annual Poster, Poetry, and Prose Contest – October 25, 2023
Illinois has had the most tornadoes in the U.S. this year. Here's why. – July 28, 2023
Chicago’s air quality: ‘We’re in the crosshairs.’ Wildfires and wind push region’s air to worst in the world, global pollution index shows. – June 27, 2023
State of Illinois expands air quality alert messaging statewide – Jul 25, 2023
Millions in Illinois Are Drinking Contaminated Water – June 29, 2023
Activists call for Chicago to rule out natural gas in new buildings, citing health risks, costs and climate change – January 19, 2023
Illinois making effort to reduce shoreline erosion – January 16, 2023
New State Water Plan spotlights 13 critical water-related challenges for Illinois – January 11, 2023
A 3M Plant in Illinois Was The Country’s Worst Emitter of a Climate-Killing ‘Immortal’ Chemical in 2021 – December 29, 2022
Illinois is leading in clean electricity, but it's falling behind elsewhere, study says – July 30, 2022
From the Farm: Losing farmland – July 20, 2022
Illinois is converting coal plants to solar projects – July 14, 2022
Illinois Poised to Improve Public Health & Economy by Adopting Clean Truck Policies – July 11, 2022
8M Illinoisans get drinking water from a utility where forever chemicals have been detected, investigation finds – July 11, 2022
The Most Traveled Bridge in Illinois That Doesn’t Meet Safety Standards – March 27, 2022
Illinois AG files suit against Marathon over crude oil spill in Cahokia Creek – March 21, 2022
Farm Bureau opposes nutrient loss bill as negotiations continue – March 2, 2022
Chicago is no safe haven from climate change – March 1, 2022
Illinois — a major feeder to the Gulf of Mexico dead zone — falls behind federal goal to reduce phosphorus and nitrogen flowing into its waterways – December 20, 2021
Little Village residents slam city for failing to reduce influx of industry: ‘As if we don’t deserve clean air’ – December 16, 2021
Fall is heating up in Illinois cities – November 29, 2021
1 million EVs: Inside the state’s plan for electrifying the transportation sector – November 23, 2021
Fertilizer Runoff In Illinois Is Still On The Rise, Despite Program Designed To Slow It Down – September 24, 2021
Habitat Loss, Traffic Noise, Runoff: 143 St. Project Concerns – September 17, 2021
Illinois Passes Nation-Leading, Equitable Climate Bill – September 12, 2021
Sierra Club demands Springfield, CWLP establish an alert system for pollution incidents – September 7, 2021
As Climate Change Ramps Up Heat, Farmers Struggle To Keep Animals Cool – Aug 30, 2021
IL mosquito populations explode in wet summer after dry spring – July 13, 2021
ICC approves Ameren's electric vehicle charging tariff – July 10, 2021
Lakefront Dump Site Opposed By Park Advocates, Southeast Siders Hasn’t Had A Valid Pollution Permit Since May 31 – June 30, 2021
As legislature reconvenes, Illinois is poised to become the first state in the Midwest to ban coal-burning power plants – June 15, 2021
This is How Much Renewable Energy Illinois is Producing – April 1, 2021
“Climate change is real;” Researchers warn extreme weather events could impact Illinois agriculture – March 31, 2021
Lax Oversight Of Coal Plant Demolitions Could Leave Illinois Communities Vulnerable – March 3, 2021