Illinois is a first-level division of United States, in North America. Its mapped cities centre on 40.5375° N, 89.0817° W.

What is the largest city in Illinois?

Chicago is the largest city mapped in Illinois, with a metropolitan population of about 8.99 million.

How many cities are in Illinois?

YearMaps maps 20 cities and towns in Illinois, with a combined metropolitan population of about 12.39 million. This counts mapped settlements, not every municipality.

Illinois Map — Cities & Geography, United States

Interactive Map of Illinois

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About Illinois

Illinois ( IL-ih-NOY) is a state in the Midwestern United States. It borders on Lake Michigan to its northeast, the Wabash and Ohio rivers to its south, and the Mississippi River generally to its west. Of the fifty U.S. states, Illinois has the fifth-largest gross domestic product (GDP), the sixth-largest population, and the 25th-most land area. Its capital city is Springfield in the center of the state, and the state's largest city is Chicago, located in northeastern Illinois.

Present-day Illinois was inhabited by Indigenous cultures for thousands of years. The French were the first Europeans to arrive, settling near the Mississippi and Illinois rivers in the 17th-century Illinois Country, as part of their sprawling colony of New France. A century later, the revolutionary war Illinois campaign prefigured American involvement in the region. Following U.S. independence in 1783, which made the Mississippi River the national boundary, American settlers began arriving from Kentucky via the Ohio River. Illinois was soon part of the United States' oldest territory, the Northwest Territory, and in 1818, it achieved statehood. The Erie Canal brought increased commercial activity in the Great Lakes, and the invention of the self-scouring steel plow by Illinoisan John Deere turned the state's rich prairie into some of the world's most productive and valuable farmland, attracting immigrant farmers from Germany, Sweden, Hungary, and elsewhere.

In the mid-19th century, the Illinois and Michigan Canal and a sprawling railroad network facilitated trade, commerce, and settlement, making the state a transportation hub for the nation, especially in Chicago, which became the world's fastest growing city by the late 19th century. By 1900, the growth of industrial jobs in the northern cities and coal mining in the central and southern areas attracted immigrants from Eastern and Southern Europe.

Summary adapted from Wikipedia: Illinois (CC BY-SA 4.0).

Illinois in Depth

History

American Indians of successive cultures lived along the waterways of what is now Illinois for thousands of years before the arrival of Europeans. The Koster Site has been excavated and demonstrates 7,000 years of continuous habitation. Cahokia, the largest regional chiefdom and urban center of the pre-Columbian Mississippian culture, was located near present-day Collinsville, Illinois. They built an urban complex of more than 100 platform and burial mounds, a 50-acre (20 ha) plaza larger than 35 football fields, and a woodhenge of sacred cedar, all in a planned design expressing the culture's cosmology. Monks Mound, the center of the site, is the largest Pre-Columbian structure north of the Valley of Mexico.

Geography

Illinois is located in the Midwest region of the United States and is one of the eight states in the Great Lakes region of North America. Illinois's eastern border with Indiana consists of a north–south line at 87° 31′ 30″ west longitude in Lake Michigan at the north, to the Wabash River in the south above Post Vincennes. The Wabash River continues as the eastern/southeastern border with Indiana until the Wabash enters the Ohio River. This marks the beginning of Illinois's southern border with Kentucky, which runs along the northern shoreline of the Ohio River. Most of the western border with Missouri and Iowa is the Mississippi River; Kaskaskia is an exclave of Illinois, lying west of the Mississippi and reachable only from Missouri.

Economy

In 2025, the gross state product for Illinois was $1.201 trillion and the state's per capita personal income was $77,772. Illinois has the 18th-largest economy in the world. In 2025, 99.6% of businesses in the state were small businesses, and employed 43.7% of Illinois's workforce. As of May 2025, the unemployment rate in Illinois was 4.8%.

As of 2026, Illinois's minimum wage is $15.00 per hour for employees over the age of 18. Tipped workers are to be paid a minimum of 60% of minimum wage.

Illinois's major agricultural outputs are corn, soybeans, hogs, cattle, dairy products, and wheat. In most years, Illinois is either the first or second state for the highest production of soybeans.

Demographics

The United States Census Bureau found that the population of Illinois was 12,812,508 in the 2020 United States census, moving from the fifth-largest state to the sixth-largest state (losing out to Pennsylvania). Illinois' population slightly declined in 2020 from the 2010 United States census by just over 18,000 residents and the overall population was quite higher than recent census estimates.Illinois is the most populous state in the Midwest region. Chicago, the third-most populous city in the United States, is the center of the Chicago metropolitan area or Chicagoland, as this area is nicknamed.

Sections adapted from Wikipedia: Illinois (CC BY-SA 4.0).

Illinois: Key Facts

Key facts about Illinois
Population	12,812,508 (2020)
Area	149,998 km²
Capital	Springfield
Head of government	JB Pritzker
Highest point	Charles Mound
Established	3 December 1818

Facts from Wikidata Q1204 (CC0).

History of Illinois: Empires and States

One mapped polity is recorded over Illinois: United States of America, 1820–2024 CE.

Polities that held Illinois, in chronological order
Polity	Period here
United States of America	1820–2024 CE

Historical Maps of Illinois

Illinois on the world map in each year one of these states held it:

Derived by testing mapped cities against dated territorial polygons. Dates are when the polygons cover this place, not the polity's whole lifespan, and polities absent from the source dataset are not listed.

Visiting Illinois

Illinois is a state in the Midwest of the United States of America. Home to the large city of Chicago, the terrain of this state ranges from rolling farmland in the south to the mud flats upon which Chicago was built.

Illinois is often referred to as the "Land of Lincoln" — Abraham Lincoln resided here for many years before becoming president. Considering how Abraham Lincoln is often regarded as one of the most influential presidents in the history of the United States, this is something the state takes pride in. It is also an important state in African-American history, with Chicago being a hub of black-owned businesses, and the country's first African-American president Barack Obama having resided here for many years before entering the White House.

Travel notes adapted from Wikivoyage: Illinois (CC BY-SA 4.0).

Largest Cities in Illinois

20 cities mapped. Ranked by metropolitan population. A port city's harbour is written up on the page of its sea.

Largest Cities in Illinois
#	Name	Population	Region	Role
1	Chicago	8.99 million	Illinois	Populated place
2	Joliet	578,460	Illinois	Populated place
3	Elgin	389,514	Illinois	Populated place
4	Evanston	350,000	Illinois	Populated place
5	Aurora	350,000	Illinois	Populated place
6	Rockford	255,978	Illinois	Populated place
7	Waukegan	200,000	Illinois	Populated place
8	Peoria	172,308	Illinois	Populated place
9	Rock Island	165,728	Illinois	Populated place
10	Urbana	144,074	Illinois	Populated place
11	Belleville	143,900	Illinois	Populated place
12	Springfield	134,715	Illinois	Admin-1 capital
13	Bloomington	128,979	Illinois	Populated place
14	Alton	84,276	Illinois	Populated place
15	Decatur	77,868	Illinois	Populated place
16	Kankakee	69,608	Illinois	Populated place
17	Quincy	47,108	Illinois	Populated place
18	Cape Girardeau	40,427	Illinois	Populated place
19	Carbondale	32,444	Illinois	Populated place
20	Galesburg	32,094	Illinois	Populated place

Ports in Illinois

4 ports mapped. Ranked by approach channel depth, the figure that limits which ships can call. Harbours link to their write-up on the page of the sea or coast they lie on. Assigned by the nearest mapped city, so features near the boundary may belong to a neighbouring division.

Ports in Illinois
#	Name	Channel Depth	Class	Sea	Max Vessel
1	Waukegan	49.4 m	Small	Great Lakes & St. Lawrence Seaway	medium vessels
2	Calumet Harbor	42.1 m	Minor	Great Lakes & St. Lawrence Seaway	large vessels
3	Chicago	42.1 m	Minor	Great Lakes & St. Lawrence Seaway	large vessels
4	Wilmette	—	Very Small	Great Lakes & St. Lawrence Seaway	medium vessels

UNESCO World Heritage Sites in Illinois

1 World Heritage Site mapped. Listed by year of inscription, earliest first. Sites shared with another country appear under each. Assigned by the nearest mapped city, so features near the boundary may belong to a neighbouring division.

UNESCO World Heritage Sites in Illinois
#	Name	Inscribed	Type	Criteria
1	Cahokia	1982	Cultural	(iii) (iv)

Illinois: Quick Answers

Where is Illinois?: Illinois is a first-level division of United States, in North America. Its mapped cities centre on 40.5375° N, 89.0817° W.
What is the largest city in Illinois?: Chicago is the largest city mapped in Illinois, with a metropolitan population of about 8.99 million.
How many cities are in Illinois?: YearMaps maps 20 cities and towns in Illinois, with a combined metropolitan population of about 12.39 million. This counts mapped settlements, not every municipality.