01
Location
Neighboring states: Indiana, Iowa, Kentucky, Missouri, Wisconsin.
Local timeSpringfield ·
U.S. States / Midwest · Card 013
Illinois
Illinois is a U.S. state in the Midwest. Its capital is Springfield.
Find Illinois
● State capital · Gold highlights Illinois.
Map: Natural Earth. Neighboring states use postal abbreviations.
Map: Natural Earth. Neighboring states use postal abbreviations.
At a glance
- Capital
- Springfield
- Postal abbreviation
- IL
- Population
- 12,719,141July 1, 2025 · Census estimate
- Total area
- 149,995 km²57,914 square miles · land and water
- Statehood
- December 3, 1818State number 21
- Currency
- U.S. dollar (USD)
Sources: Census · population · Census · area
Illinois in context
Gold shows Illinois. The dot marks Springfield.
Alaska and Hawaii are shown in separate insets at different scales.Geography & flag
02
Landscape & places
Lincoln Home National Historic Site preserves Abraham Lincoln's home and part of his Springfield neighborhood.
03
Land and water
The total area includes 143,793 km² of land and 6,202 km² of water, according to Census area measurements.
State flag
The state seal on a white field, with Illinois written below.
Sources: Census · geographic reference · Census · area measurements · National Park Service · Lincoln Home
History & statehood
Illinois was part of the Northwest Territory established in 1787. Illinois Territory was separated from Indiana Territory in 1809, and Illinois entered the Union in 1818. Abraham Lincoln's Springfield home preserves part of the state's nineteenth-century political history.
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Area included in the Northwest Territory
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Illinois Territory formed
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Statehood · State number 21
Sources: Congressional Research Service · statehood · U.S. Census Bureau · historical geography · National Park Service
Economy
Main activities
In 2025, professional and business services was the largest of the broad industry groups compared here by current-dollar output. Other major groups included real estate and rental and leasing, manufacturing, and government and government enterprises.
Total economic output was $1,202.0 billion in current dollars in 2025.
Largest industry groups · 2025
- Professional and business services: 13.5%
- Real estate and rental and leasing: 12.8%
- Manufacturing: 11.0%
- Government and government enterprises: 9.1%
Share of total current-dollar GDP. These figures measure output, not employment.
Sources: BEA · annual GDP by state, SAGDP2
Population & economic trends
Population, 2020–2025
Millions of people12.722025 · millions of people
July 1 resident population estimates, using the Census Bureau’s Vintage 2025 series.
Sources: U.S. Census Bureau
View data table
| Year | People |
|---|---|
| 2020 | 12,795,348 |
| 2021 | 12,703,354 |
| 2022 | 12,609,577 |
| 2023 | 12,633,389 |
| 2024 | 12,703,033 |
| 2025 | 12,719,141 |
Real GDP, 2010–2025
Billions of chained 2017 dollars913.682025 · billions of chained 2017 dollars
Real GDP measures economic output adjusted for inflation. The chart uses BEA’s chained 2017 dollars.
Sources: U.S. Bureau of Economic Analysis
View data table
| Year | Millions of chained 2017 dollars |
|---|---|
| 2010 | 755,391.4 |
| 2011 | 772,225.6 |
| 2012 | 790,723.3 |
| 2013 | 795,435.2 |
| 2014 | 811,490.1 |
| 2015 | 825,424.9 |
| 2016 | 826,404.7 |
| 2017 | 832,826.8 |
| 2018 | 851,517.2 |
| 2019 | 858,018.3 |
| 2020 | 810,693.1 |
| 2021 | 857,114.6 |
| 2022 | 872,907.5 |
| 2023 | 884,965.3 |
| 2024 | 899,125.9 |
| 2025 | 913,681.4 |
Government
Illinois has three branches of state government. The governor leads the executive branch. A Senate and House of Representatives form the legislature, which passes state laws and budgets. State courts interpret and apply the law.
Sources: USAGov · Illinois
Knowledge check
Three questions about Illinois.
QUESTION 1 OF 3
What is the capital of Illinois?
Sources & notes
Prepared 27 September 2026. Population: Census Bureau Vintage 2025, July 1 estimates for 2020–2025. Real GDP: BEA annual state accounts, SAGDP9, millions of chained 2017 dollars; industry shares: SAGDP2, current dollars. Data downloaded 27 September 2026. Area measurements include land and water.
Sources: Census · population estimates · BEA · state GDP · Census · area measurements · Natural Earth · map data
The capital clock shows current local time. Statistical figures are dated estimates and may be revised.