The following outline is provided as an overview of and topical guide to the U.S. state of Illinois:
Illinois – fifth most populous of the 50 states of the United States of America. Illinois lies between Lake Michigan and the Mississippi River and the Ohio River in the Midwestern United States. Chicago, Illinois, is the third most populous city and the third most populous metropolitan area of the United States. The United States created the Illinois Territory on March 1, 1809. Illinois joined the Union as the 21st state on December 3, 1818.
General reference
Names
Common name: Illinois
Pronunciation: Official name: State of Illinois Abbreviations and name codes Postal symbol: IL ISO 3166-2 code: US-IL Internet second-level domain: .il.us Nicknames Land of Lincoln (currently used on license plates) Prairie State Corn State Inland Empire State Sucker State (possibly named for a type of fish) Garden of the West Baja Wisconsin Adjectival: Illinois Demonym: Illinoisan
Geography of Illinois
Geography of Illinois
Illinois is: a U.S. state, a federal state of the United States of America
Location
Northern hemisphere
Western hemisphere
Americas
North America
Anglo America
Northern America
United States of America
Contiguous United States
Central United States
Corn Belt
East North Central States
Midwestern United States
Great Lakes Region
Population of Illinois: 12,830,632 (2010 U.S. Census) Area of Illinois: , 25th of the 50 states. Atlas of Illinois
Places in Illinois
Historic places in Illinois
Ghost towns in Illinois
National Historic Landmarks in Illinois
National Register of Historic Places listings in Illinois
Bridges on the National Register of Historic Places in Illinois
National Natural Landmarks in Illinois
National parks in Illinois
State parks in Illinois
Environment of Illinois
Climate of Illinois
Geology of Illinois
Environment ecoregions of Illinois
Protected areas in Illinois
Nature centers in Illinois
State forests of Illinois
Superfund sites in Illinois
Wildlife of Illinois
Fauna of Illinois
Birds of Illinois
Natural geographic features of Illinois
Lakes of Illinois
Rivers of Illinois
Regions of Illinois
Regions of Illinois
Central Illinois
Eastern Illinois
Northern Illinois
Northwestern Illinois
Southern Illinois
Southeastern Illinois
Forgottonia (Western Illinois)
Administrative divisions of Illinois
The 102 counties of the state of Illinois
Municipalities in Illinois
Cities in Illinois
State capital of Illinois: City nicknames in Illinois Towns in Illinois Unincorporated communities in Illinois Census-designated places in Illinois
Demography of Illinois
Demographics of Illinois
Government and politics of Illinois
Politics of Illinois
Form of government: U.S. state government
United States congressional delegations from Illinois
Illinois State Capitol
Elections in Illinois
Electoral reform in Illinois
Political party strength in Illinois
Branches of the government of Illinois
Government of Illinois
Executive branch of the government of Illinois
Governor of Illinois
Lieutenant Governor of Illinois
Illinois Secretary of State
Illinois Treasurer
State departments
Illinois Department of Transportation
Legislative branch of the government of Illinois
Illinois General Assembly (bicameral) Upper house: Illinois Senate Lower house: Illinois House of Representatives