What is the capital of Illinois?

The capital of Illinois is Springfield, home to the Abraham Lincoln Presidential Library and Museum and numerous historic Lincoln sites.

How many people live in Illinois?

Illinois has a population of approximately 12.8 million people, making it the 6th most populous state in the U.S.

When was Illinois admitted to the Union?

Illinois was admitted to the Union on December 3, 1818, becoming the 21st state.

What is Illinois known for?

Illinois is known for Chicago's iconic skyline and deep-dish pizza, Abraham Lincoln's legacy, the world's first skyscraper, Fermilab, and being one of the nation's top producers of corn and soybeans.

Illinois

Land of Lincoln

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Quick Stats

12.8MPopulation

#6Rank

1818Joined

57.9kArea (mi²)

Map

Seal & Motto

"State Sovereignty, National Union"

Additional Information

AbbreviationIL

Motto Origin

Reflects the tension between state and federal rights.

Adopted 1818.

Official WebsiteIllinois.gov

Population Growth

Overview

Illinois, the 'Prairie State' and 'Land of Lincoln,' is the cultural and industrial anchor of the Midwest. Boasting a world-class global city in Chicago and some of the nation's most fertile farmland, it is a leading center for international finance, logistics, transportation, and agricultural innovation today.

Historical Significance

Illinois officially joined the Union on December 3, 1818, as the 21st state. Its historical trajectory has seen it transform from a rugged frontier for fur trading into a pivotal Union stronghold during the Civil War, and eventually into the industrial heart of America and a primary destination for the Great Migration.

Top Cities & Hubs

Chicago

Population: ~2.7M

The "Windy City," a global metropolis and the financial capital of the Midwest, world-famous for its bold architecture, world-class museums, and its legendary commodities trading markets.

Aurora

Population: ~200,000

Known as the "City of Lights" for being the first city in the U.S. to have all-electric street lighting, it is a diverse industrial and manufacturing hub in the greater Chicago metro.

Joliet

Population: ~150,000

A key transportation hub located along the Des Plaines River, famed for its historic Rialto Theatre, Chicagoland Speedway, and its role as a logistics center for the region.

Rockford

Population: ~148,000

Known as the "Forest City," this manufacturing center along the Rock River is famous for its nationally recognized Japanese garden and a thriving aerospace and automotive industry.

Naperville

Population: ~147,000

Consistently ranked one of the best places to live in the U.S., this wealthy Chicago suburb is a major technology and research hub with a vibrant walkable downtown.

Neighbors

Region: Midwest

Capital: Springfield

Key Landmarks & Economy

Willis Tower: Formerly the world's tallest building for 25 years, the Willis Tower (Sears Tower) remains an iconic symbol of Chicago's bold architectural ambition.

Lincoln Home NHS: Abraham Lincoln's home in Springfield is a National Historic Site where the 16th President lived for 17 years before his presidency, open to millions of visitors.

Agriculture & Science: Illinois is a global leader in corn and soybean production and home to both Fermilab and Argonne National Laboratory, two of the world's premier research centers.

Did You Know?

Illinois was the first state to ratify the 13th Amendment abolishing slavery, doing so on February 1, 1865.
The Cahokia Mounds near Collinsville are the site of the largest prehistoric Native American settlement north of Mexico, a UNESCO World Heritage Site.
The world's first skyscraper — the 10-story Home Insurance Building — was constructed in Chicago in 1885, fundamentally transforming urban architecture.