The Flag of the State of Illinois

The Seal of the State of Illinois

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: /ˌɪlɪˈnɔɪ/ ^ⓘ IL-i-NOY
  • 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^[1] (currently used on license plates)
    • Prairie State^[1]
    • Corn State^[1]
    • Inland Empire State
    • Sucker State (possibly named for a type of fish)^[1]
    • Garden of the West^[1]
    • Baja Wisconsin^[1]
• 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^[2])
• Area of Illinois: 57,918 square miles (150,010 km²), 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

Judicial branch of the government of Illinois

Courts of Illinois

• Supreme Court of Illinois

Law and order in Illinois

Law of Illinois

• Cannabis in Illinois
• Capital punishment in Illinois
  • Individuals executed in Illinois
• Illinois Constitution
• Crime in Illinois
• Gun laws in Illinois
• Law enforcement in Illinois
  • Law enforcement agencies in Illinois
    • Illinois State Police
• Same-sex marriage in Illinois

Military in Illinois

• Illinois Air National Guard
• Illinois Army National Guard
• List of United States military bases in Illinois

History of Illinois

History of Illinois

History of Illinois, by period

• Prehistory of Illinois
  • Indigenous peoples
    • Mississippian culture
      • Cahokia
• French colony of Louisiane, 1699–1763; Upper Louisiana was called Illinois Country.
  • Treaty of Paris of 1763
• British (though predominantly Francophone) Province of Quebec, (1763–1783)-1791
• American Revolutionary War, April 19, 1775 – September 3, 1783
  • United States Declaration of Independence, July 4, 1776
  • Illinois campaign, July 1778 – February 1779
  • Treaty of Paris, September 3, 1783
  • Unorganized territory of the United States, 1783–1787
• Territory Northwest of the River Ohio, (1787–1800)-1803
• Territory of Indiana, (1800–1809)-1816
• Territory of Illinois, 1809–1818
  • Peoria War, 1813
• State of Illinois becomes 21st State admitted to the United States of America on December 3, 1818
  • Black Hawk War, 1832
  • Abraham Lincoln becomes 16th President of the United States on March 4, 1861
  • American Civil War, April 12, 1861 – May 13, 1865
    • Illinois in the American Civil War
    • Assassination of President Abraham Lincoln in Washington, D.C., on April 14, 1865
      • President Lincoln dies in Washington, D.C., on April 15, 1865
  • Ulysses S. Grant becomes 18th President of the United States on March 4, 1869
  • Ronald Reagan becomes 40th President of the United States on January 20, 1981

History of Illinois, by region

• By city
  • History of Chicago
  • History of Nauvoo, Illinois
  • History of Peoria, Illinois

History of Illinois, by subject

• Museums in Illinois

Culture of Illinois

Culture of Illinois

• Museums in Illinois
• Religion in Illinois
  • Episcopal Diocese of Chicago
• Scouting in Illinois
• List of Illinois state symbols
  • Flag of Illinois
  • Seal of Illinois

The Arts in Illinois

• Music of Illinois
• Theater in Illinois

Sports in Illinois

Sports in Illinois

• Professional sports teams in Illinois

Economy and infrastructure of Illinois

Economy of Illinois

• Communications in Illinois
  • Newspapers in Illinois
  • Radio stations in Illinois
  • Television stations in Illinois
• Energy in Illinois
  • Power stations in Illinois
  • Solar power in Illinois
  • Wind power in Illinois
• Health care in Illinois
  • Hospitals in Illinois
• Transportation in Illinois
  • Airports in Illinois
  • Railroads in Illinois
  • Roads in Illinois
    • Illinois Routes (State highways)
    • Interstate Highways in Illinois

Education in Illinois

Education in Illinois

• Schools in Illinois
  • School districts in Illinois
    • High schools in Illinois
  • Colleges and universities in Illinois
    • University of Illinois system
    • Illinois State University