Editing Illinois (section)

==History==

{{Main|History of Illinois}}

=== Pre-European ===
[[File:Upper Bluff Lake Dancing Figures plate HRoe 2012.jpg|thumb|left|[[Mississippian copper plate]] found at the Saddle Site in [[Union County, Illinois]]]]
[[Indigenous peoples of the Americas|American Indians]] of successive cultures lived along the waterways of the Illinois area 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|Urban Center]] of the [[Pre-Columbian era|Pre-Columbian]] [[Mississippian culture]], was located near present-day [[Collinsville, Illinois]]. They built an urban complex of more than 100 [[platform mound|platform]] and [[burial mound]]s, a {{cvt|50|acre|4=0|adj=on}} [[plaza]] larger than 35 football fields,<ref name="PAUKETATCAHOKIA">{{cite book |author-link=Timothy Pauketat |first=Timothy R. |last=Pauketat |title=Cahokia: Ancient America's Great City on the Mississippi |series=Penguin library of American Indian history |publisher=[[Viking Press]] |year=2009 |isbn=978-0-670-02090-4 |oclc=276819729 |pages=23–34 |quote="Cahokia was so large—covering three to five square miles—that archaeologists have yet to probe many portions of it. Its centerpiece was an open fifty-acre Grand Plaza, surrounded by packed-clay pyramids. The size of thirty-five football fields, the Grand Plaza was at the time the biggest public space ever conceived and executed north of Mexico&nbsp;... a flat public square 1,600-plus feet in length and 900-plus feet in width."}}</ref> 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]]. It is {{cvt|100|ft}} high, {{cvt|951|ft}} long, {{cvt|836|ft}} wide, and covers {{cvt|13.8|acre}}.<ref name="SKELE">{{Cite book |last=Skele |first=Mikels |url=https://archive.org/stream/greatknobinterpr00skel#page/102/mode/2up |title=The Great Knob: Interpretations of Monks Mound |series=Studies in Illinois Archaeology |publisher=Illinois Historic Preservation Agency |location= Springfield, IL |year=1988 |isbn=978-0-942579-03-1 |issue=4 |access-date=November 12, 2015}}</ref> It contains about {{cvt|814000|cuyd}} of earth.<ref name="SNOW2010">{{cite book |last=Snow |first=Dean R. |title=Archaeology of Native North Americas |year=2010 |publisher=Prentice Hall |location=Upper Saddle River, NJ |pages=201–203 |isbn=9780136156864 |oclc=223933566}}</ref> It was topped by a structure thought to have measured about {{cvt|105|ft}} in length and {{cvt|48|ft}} in width, covered an area {{cvt|5000|sqft}}, and been as much as {{cvt|50|ft}} high, making its peak {{cvt|150|ft}} above the level of the plaza. The finely crafted ornaments and tools recovered by archaeologists at [[Cahokia]] include elaborate ceramics, finely sculptured stonework, carefully embossed and engraved copper and [[mica]] sheets, and one funeral blanket for an important chief fashioned from 20,000 shell beads. These artifacts indicate that Cahokia was truly an urban center, with clustered housing, markets, and specialists in toolmaking, hide dressing, potting, jewelry making, shell engraving, weaving and salt making.<ref>{{cite book|last=Nash|first=Gary B.|title=Red, White, and Black: The Peoples of Early North America|publisher=Pearson|isbn=9780205887590|location=Boston|year=2015|edition=7th|page=6}}</ref>

The civilization vanished in the 15th century for unknown reasons, but historians and archeologists have speculated that the people depleted the area of resources. Many indigenous tribes engaged in constant warfare. According to Suzanne Austin Alchon, "At one site in the central [[Illinois River]] valley, one third of all adults died as a result of violent injuries."<ref>{{Cite book |last=Austin Alchon |first=Suzanne |title=A pest in the land: new world epidemics in a global perspective |url=https://books.google.com/books?id=YiHHnV08ebkC&pg=PA59 |publisher=University of New Mexico Press |year=2003 |page=59 |isbn=978-0-8263-2871-7 |access-date=June 16, 2015 |archive-date=August 3, 2020 |archive-url=https://web.archive.org/web/20200803102909/https://books.google.com/books?id=YiHHnV08ebkC&pg=PA59 |url-status=live }}</ref> The next major power in the region was the [[Illinois Confederation]] or Illini, a political alliance.<ref>{{cite book|last=Hoxie|first=E.|title=Encyclopedia of North American Indians|year=1996|pages=266–267, 506}}</ref> Around the time of European contact in 1673, the Illinois confederation had an estimated population of over 10,000 people.<ref name="museum.state.il.us">{{Cite web |title=Native Americans:Historic:The Illinois:History:The Illinois Decline |url=https://www.museum.state.il.us/muslink/nat_amer/post/htmls/hi_decline.html |access-date=2024-06-20 |website=www.museum.state.il.us}}</ref> As the Illini declined during the [[Beaver Wars]] era, members of the [[Algonquian languages|Algonquian]]-speaking [[Potawatomi]], [[Miami people|Miami]], [[Sauk people|Sauk]], and other tribes including the Fox ([[Meskwaki]]), [[Iowa people|Iowa]], [[Kickapoo people|Kickapoo]], [[Mascouten]], [[Piankeshaw]], [[Shawnee]], [[Wea]], and Winnebago ([[Ho-Chunk]]) came into the area from the east and north around the Great Lakes.<ref name="Nelson" /><ref>{{cite web |url=http://www.museum.state.il.us/muslink/nat_amer/post/ |title=Native Americans:American Indian Tribes of Illinois |publisher=Illinois State Museum |date=October 2, 2002 |access-date=February 27, 2016 |archive-url=https://web.archive.org/web/20160322071318/http://www.museum.state.il.us/muslink/nat_amer/post/ |archive-date=March 22, 2016}}</ref>

===European exploration and settlement prior to 1800===

{{Main|New France|Louisiana (New France)|Canada (New France)|Illinois Country|French and Indian War|Treaty of Paris (1763)|Province of Quebec (1763–1791)|Indian Reserve (1763)|American Revolutionary War|Western theater of the American Revolutionary War|Illinois County, Virginia|Treaty of Paris (1783)|Northwest Ordinance|Northwest Territory}}

[[File:Illinois 1718.jpg|thumb|Illinois in 1718, approximate modern state area highlighted, from {{lang|fr|Carte de la Louisiane et du cours du Mississipi}} by [[Guillaume de L'Isle]]<ref>{{cite web |url=http://www2.lib.virginia.edu/exhibits/lewis_clark/exploring/ch2-10.html |title=Carte de la Louisiane et du Cours du Mississipi. 1718 |last=de L'Isle |first=Guillaume |author-link=Guillaume Delisle |year=1718 |website=An Exhibition of Maps and Navigational Instruments on View |publisher=University of Virginia |access-date=January 25, 2010 |location=Tracy W. McGregor Room, Alderman Library |archive-url=https://web.archive.org/web/20150716074149/http://explore.lib.virginia.edu/exhibits/show/lewisclark |archive-date=July 16, 2015 |url-status=dead}}</ref>]]

French explorers [[Jacques Marquette]] and [[Louis Jolliet]] explored the [[Illinois River]] in 1673. Marquette soon after founded a mission at the [[Grand Village of the Illinois]] in [[Illinois Country]]. In 1680, French explorers under [[René-Robert Cavelier, Sieur de La Salle]] and [[Henri de Tonti]] constructed a fort at the site of present-day [[Peoria, Illinois|Peoria]], and in 1682, a fort atop [[Starved Rock]] in today's Starved Rock State Park. French Empire [[Canadiens]] came south to settle particularly along the Mississippi River, and Illinois was part of first [[New France]], and then of [[La Louisiane]] until 1763, when it passed to the British with their defeat of France in the [[Seven Years' War]]. The small French settlements continued, although many French migrated west to [[Ste. Genevieve, Missouri|Ste. Genevieve]] and [[St. Louis, Missouri]], to evade British rule.<ref name="Biles" />

A few British soldiers were posted in Illinois, but few British or American settlers moved there, as the Crown made it part of the territory reserved for Indians west of the Appalachians, and then part of the [[Province of Quebec (1763–1791)|British Province of Quebec]]. In 1778, [[George Rogers Clark]] claimed [[Illinois County]] for [[Colony of Virginia|Virginia]]. In a compromise, Virginia (and other states that made various claims) ceded the area to the new United States in the 1780s and it became part of the [[Northwest Territory]], administered by the federal government and later organized as states.<ref name="Biles">{{cite book |last=Biles |first=Roger |title=Illinois: A History of the Land and its People |year=2005 |publisher=Northern Illinois University Press |location=DeKalb |isbn=978-0-87580-349-4}}</ref>

===19th century===

{{Main|Indiana Territory|Organic act#List of organic acts|Illinois Territory|Admission to the Union|List of U.S. states by date of admission to the Union}}

{{See also|History of Chicago|History of Nauvoo, Illinois}}

====Prior to statehood====
[[File:Kaskaskia Bell 3321.jpg|thumb|right|The bell donated by King Louis XV in 1741 to the French mission at Kaskaskia. It was later called the "Liberty Bell of the West", after it was rung to celebrate U.S. victory in the Revolution]]
The [[Illinois-Wabash Company]] was an early claimant to much of Illinois. The [[Illinois Territory]] was created on February 3, 1809, with its capital at [[Kaskaskia, Illinois|Kaskaskia]], an early French settlement.

During the discussions leading up to Illinois's [[admission to the Union]], the proposed northern boundary of the state was moved twice.<ref>{{cite web |url=http://www.sancohis.org/presentations/Illinois%20From%20Territory%20to%20State.htm |title=Full Remarks from Dave M |publisher=Sancohis.org |date=March 16, 2010 |access-date=February 7, 2011}}{{Dead link|date=February 2012}}</ref> The original provisions of the [[Northwest Ordinance]] had specified a boundary that would have been tangent to the southern tip of Lake Michigan. Such a boundary would have left Illinois with no shoreline on Lake Michigan at all. However, as Indiana had successfully been granted a {{cvt|10|mi|adj=on}} northern extension of its boundary to provide it with a usable lakefront, the original bill for Illinois statehood, submitted to Congress on January 23, 1818, stipulated a northern border at the same latitude as Indiana's, which is defined as 10 miles north of the southernmost extremity of Lake Michigan. However, the Illinois delegate, [[Nathaniel Pope]], wanted more, and lobbied to have the boundary moved further north. The final bill passed by Congress included an amendment to shift the border to 42° 30' north, which is approximately {{cvt|51|mi}} north of the Indiana northern border. This shift added {{cvt|8500|sqmi|4=-2}} to the state, including the [[lead mining]] region near [[Galena, Illinois|Galena]]. More importantly, it added nearly 50 miles of Lake Michigan shoreline and the Chicago River. Pope and others envisioned a canal that would connect the Chicago and Illinois rivers and thus connect the Great Lakes to the Mississippi.

====The State of Illinois prior to the Civil War====

[[File:United States 1818-12-1819-03.png|thumb|In 1818, Illinois became the 21st U.S. state. The southern portion of [[Illinois Territory]] was admitted as the state of Illinois, and the rest was joined to [[Michigan Territory]].]]
[[File:Edward_Coles.png|thumb|right|150px|The second [[Governor of Illinois]], [[Edward Coles]] brought his slaves from his home state of [[Virginia]] to give them their [[manumission|freedom]] when they arrived in Illinois.]]
[[File:Springfield,Illinois-Old State Capitol.jpg|thumb|[[Old State Capitol State Historic Site|Old State Capitol]]: Abraham Lincoln and other area legislators were instrumental in moving the state capitol to centrally located Springfield in 1839.]]

In 1818, Illinois became the 21st U.S. state. The capital remained at Kaskaskia, headquartered in a small building rented by the state. In 1819, [[Vandalia, Illinois|Vandalia]] became the capital, and over the next 18 years, three separate buildings were built to serve successively as the capitol building. In 1837, the state legislators representing [[Sangamon County]], under the leadership of state representative [[Abraham Lincoln]], succeeded in having the capital moved to [[Springfield, Illinois|Springfield]],<ref>{{cite web |url=http://abrahamlincolnsclassroom.org/Library/newsletter.asp?ID=137&CRLI=193 |title=Abraham Lincoln and Springfield |publisher=Abraham Lincoln's Classroom |access-date=February 7, 2011 |archive-url=https://web.archive.org/web/20120517032613/http://abrahamlincolnsclassroom.org/Library/newsletter.asp?ID=137&CRLI=193 |archive-date=May 17, 2012 |url-status=dead}}</ref> where a [[Old State Capitol State Historic Site (Illinois)|fifth capitol]] building was constructed. A [[Illinois State Capitol|sixth capitol]] building was erected in 1867, which continues to serve as the Illinois capitol today.

Though it was ostensibly a "[[Slave and free states|free state]]", there was nonetheless [[History of slavery in Illinois|slavery in Illinois]]. The ethnic French had owned black slaves since the 1720s, and American settlers had already brought slaves into the area from [[Kentucky]]. Slavery was nominally banned by the Northwest Ordinance, but that was not enforced for those already holding slaves. When Illinois became a state in 1818, the Ordinance no longer applied, and about 900 slaves were held in the state. As the southern part of the state, later known as "Egypt" or "Little Egypt",<ref>{{cite news |last=Simon|first=John Y.|url=https://www.chicagotribune.com/2001/06/24/the-other-illinois-how-egypt-lost-its-clout/ |title=The other Illinois: How Egypt lost its clout |publisher=Chicago Tribune |date=June 24, 2001 |access-date=April 29, 2012 |archive-url=https://web.archive.org/web/20150714034522/http://articles.chicagotribune.com/2001-06-24/news/0106240357_1_illinois-egypt-logan |archive-date=July 14, 2015 |url-status=live}}</ref><ref>{{cite news |last=Davis| first=Rich |url=http://www.courierpress.com/news/2010/may/02/backroads-tourism/ |title=Southern Illinois Backroads Tourism: In Little Egypt it means bluffs, Superman, even scuba diving |publisher=Evansville Courier & Press |access-date=April 29, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20130117082832/http://www.courierpress.com/news/2010/may/02/backroads-tourism/ |archive-date=January 17, 2013}}</ref> was largely settled by migrants from the South, the section was hostile to free blacks. [[Edward Coles]], the second Governor of Illinois who was born in Virginia, participated in a campaign to block extending existing slavery in Illinois after winning the [[1822 Illinois gubernatorial election]]. In 1824, state residents voted against making slavery legal by a vote of 6640 against to 4972 for.<ref>{{cite web|url=http://www.poemsforfree.com/cc25.html |title=Chapter 25 : The Result |publisher=Poemsforfree.com |access-date=2015-06-11}}</ref>

Still, most residents opposed allowing free blacks as permanent residents. Some settlers brought in slaves seasonally or as house servants.<ref>{{cite book|last=Finkelman |first=Paul |title=Slavery and the Founders: Race and Liberty in the Age of Jefferson |year=2001 |page=78 |edition=2nd |publisher=M. E. Sharpe |location=Armonk, NY |isbn=9780765604385}}</ref> The [[Constitution of Illinois|Illinois Constitution of 1848]] was written with a provision for exclusionary laws to be passed. In 1853, [[John A. Logan]] helped pass a law to prohibit all African Americans, including [[Freedman|freedmen]], from settling in the state.<ref>{{cite book|first=James Pickett |last=Jones |title=Black Jack: John A. Logan and Southern Illinois in the Civil War Era |date=1995 |publisher=SIU Press |orig-date=1967| isbn=0-8093-2002-9 |oclc=31435846}}</ref>

The [[The Snow Winter of 1880–1881|winter of 1830–1831]] is called the "Winter of the Deep Snow";<ref>{{cite news |title=1830-1831: The Winter of the Deep Snow |url=https://www.sj-r.com/story/news/columns/2012/02/02/1830-1831-winter-deep/44269013007/ |publisher=State Journal-Register |access-date=November 9, 2022 |date=February 1, 2012 |archive-date=December 4, 2022 |archive-url=https://web.archive.org/web/20221204125236/https://www.sj-r.com/story/news/columns/2012/02/02/1830-1831-winter-deep/44269013007/ |url-status=live }}</ref> a sudden, deep snowfall blanketed the state, making travel impossible for the rest of the winter, and many travelers perished. Several severe winters followed, including the "Winter of the Sudden Freeze". On December 20, 1836, a fast-moving cold front passed through, freezing puddles in minutes and killing many travelers who could not reach shelter. The adverse weather resulted in crop failures in the northern part of the state. The southern part of the state shipped food north, and this may have contributed to its name, "[[Southern Illinois|Little Egypt]]", after the Biblical story of [[Joseph (Genesis)|Joseph in Egypt]] supplying grain to his brothers.<ref>{{cite web | title=Egypt |last=Duff |first=Andrew D. |url=http://www.springhousemagazine.com/egypt2.htm |website=Springhouse Magazine |archive-url=https://web.archive.org/web/20130117082839/http://www.springhousemagazine.com/egypt2.htm |archive-date=January 17, 2013 |access-date=May 1, 2006}}</ref>

In 1832, the [[Black Hawk War]] was fought in Illinois and present-day [[Wisconsin]] between the United States and a coalition of the [[Sauk people|Sauk]], [[Meskwaki|Fox (Meskwaki)]], and [[Kickapoo people|Kickapoo]] Indian tribes, who had been forced to leave their homes and relocate to Iowa in 1831. The tribes had lost their territory east of the Mississippi river in Illinois under a [[Treaty of St. Louis (1804)|disputed treaty]] in 1804. The Indians, under Sauk Chief [[Black Hawk (Sauk leader)|Black Hawk]], attempted to return to Illinois in April 1832 to reclaim this land. They were attacked and defeated by the [[Militia (United States)|U.S. Militia]] and rival tribes allied with the US forces, including the [[Potawatomi]], [[Lakota people|Dakota]], [[Menominee]], and [[Ho-Chunk]]. The survivors of Black Hawk's band were forced back to Iowa.<ref>{{cite web |author=Lewis, James |title=The Black Hawk War of 1832 |url=http://lincoln.lib.niu.edu/blackhawk/ |archive-url=https://web.archive.org/web/20120801011703/http://lincoln.lib.niu.edu/blackhawk/ |archive-date=August 1, 2012 |access-date=August 10, 2012 |publisher=Abraham Lincoln Historical Digitization Project}}</ref> This represented the end of Indian resistance to white settlement in the Chicago and Northern Illinois regions.<ref>{{cite encyclopedia |url=http://encyclopedia.chicagohistory.org/pages/141.html |title=Black Hawk War |encyclopedia=Encyclopedia of Chicago |access-date = August 10, 2012 |archive-url = https://web.archive.org/web/20120822134545/http://www.encyclopedia.chicagohistory.org/pages/141.html |archive-date = August 22, 2012}}</ref>  By 1832, when the last Indian lands in Illinois were ceded to the United States, the indigenous population of the state had been reduced by infectious diseases, warfare, and [[Indian removal|forced westward removal]] to only one village with fewer than 300 inhabitants.<ref name="museum.state.il.us"/>

By 1839, the [[Latter Day Saints]] had founded a [[utopian]] city called [[Nauvoo, Illinois|Nauvoo]], formerly called Commerce. Located in [[Hancock County, Illinois|Hancock County]] along the [[Mississippi River]], Nauvoo flourished and, by 1844, briefly surpassed Chicago for the position of the state's largest city.<ref>{{Cite journal |last=Easton Black |first=Susan |date=1995 |title=How Large Was the Population of Nauvoo? |url=https://byustudies.byu.edu/article/how-large-was-the-population-of-nauvoo/ |journal=BYU Studies Quarterly |volume=35 |issue=2 |pages=91–94 |access-date=December 4, 2023 |archive-date=December 4, 2023 |archive-url=https://web.archive.org/web/20231204005818/https://byustudies.byu.edu/article/how-large-was-the-population-of-nauvoo/ |url-status=live }}</ref><ref>{{Cite web |date=9 November 2022 |title=Early Chicago, 1833–1871 |url=https://www.ilsos.gov/departments/archives/teaching_packages/early_chicago/doc23.html |access-date=9 November 2022 |website=ilsos.gov |archive-date=November 9, 2022 |archive-url=https://web.archive.org/web/20221109230005/https://www.ilsos.gov/departments/archives/teaching_packages/early_chicago/doc23.html |url-status=live }}</ref> But in that same year, the [[Latter Day Saint movement]] founder, [[Joseph Smith]], [[Death of Joseph Smith|was killed]] in the [[Carthage Jail]], about 30 miles away from Nauvoo. Following a [[succession crisis (Latter Day Saints)|succession crisis]], [[Brigham Young]] led most Latter Day Saints out of Illinois in a [[Mormon pioneers|mass exodus]] to present-day [[Utah]]; after close to six years of rapid development, Nauvoo quickly declined afterward.

After it was established in 1833, [[Chicago]] gained prominence as a [[Great Lakes]] port, and then as an [[Illinois and Michigan Canal]] port after 1848, and as a rail hub soon afterward. By 1857, Chicago was Illinois's largest city.<ref name="Biles" /> With the tremendous growth of mines and factories in the state in the 19th century, Illinois was the ground for the formation of [[labor unions in the United States]].

In 1847, after lobbying by [[Dorothea Dix|Dorothea L. Dix]], Illinois became one of the first states to establish a system of state-supported treatment of mental illness and disabilities, replacing local [[almshouse]]s. Dix came into this effort after having met J. O. King, a [[Jacksonville, Illinois]] businessman, who invited her to Illinois, where he had been working to build an asylum for the insane. With the lobbying expertise of Dix, plans for the Jacksonville State Hospital (now known as the [[Jacksonville Developmental Center]]) were signed into law on March 1, 1847.<ref>{{cite journal |last1=Norbury |first1=Frank |title=Dorothea Dix and the Founding of Illinois's First Mental Hospital |journal=Journal of the Illinois State Historical Society |date=Spring 1999 |volume=92 |issue=1 |pages=13–29 |jstor=40193299}}</ref>

====Civil War and after====

{{Main|Illinois in the American Civil War}}

[[File:Embarkation of General McClernand's Brigade at Cairo.jpg|thumb|right|[[Union (American Civil War)|Union]] troops embarking at [[Cairo, Illinois|Cairo]] on January 10, 1862]]

During the [[American Civil War]], Illinois ranked fourth in soldiers who served (more than 250,000) in the [[Union Army]], a figure surpassed by only New York, [[Pennsylvania]], and [[Ohio]]. Beginning with President [[Abraham Lincoln]]'s first call for troops and continuing throughout the war, Illinois mustered 150 infantry regiments, which were numbered from the 7th to the 156th regiments. Seventeen cavalry regiments were also gathered, as well as two light artillery regiments.<ref>{{cite web|url=http://www.illinoiscivilwar.org/units_num.html| title=Illinois Infantry, Cavalry, and Artillery Units|url-status=usurped|archive-url=https://web.archive.org/web/20180818150741/http://www.illinoiscivilwar.org/units_num.html |archive-date=August 18, 2018 }}</ref> The town of [[Cairo, Illinois|Cairo]], at the southern tip of the state at the confluence of the Mississippi and Ohio Rivers, served as a strategically important supply base and training center for the [[Union (American Civil War)|Union]] army. For several months, both General [[Ulysses S. Grant|Grant]] and Admiral [[Andrew Hull Foote|Foote]] had headquarters in Cairo.

During the Civil War, and more so afterwards, Chicago's population skyrocketed, which increased its prominence. The [[Pullman Strike]] and [[Haymarket affair|Haymarket Riot]], in particular, greatly influenced the development of the American [[labour movement|labor movement]]. From Sunday, October 8, 1871, until Tuesday, October 10, 1871, the [[Great Chicago Fire]] burned in downtown Chicago, destroying {{cvt|4|sqmi|spell=in}}.<ref>{{cite book|first=Roland |last=Tweet |title=Miss Gale's Books: The Beginnings of the Rock Island Public Library |location=Rock Island, IL |publisher=Rock Island Public Library |year=1997 |page=15}}</ref>

===20th century===
[[File:Protestors and Chicago Police Officers in Grant Park - DPLA - 2972723d78e7f60f542da94846a6f9a6 (1) (cropa).jpg|thumb|Police and protesters at the [[1968 Democratic National Convention]] in Chicago.]]
[[File:Alton Illinois sinking in 1993.jpg|thumb|upright|Rising waters in [[Alton, Illinois|Alton]] in 1993.]]
At the turn of the 20th century, Illinois had a population of nearly 5&nbsp;million. Many people from other parts of the country were attracted to the state by employment caused by the expanding industrial base. Whites were 98% of the state's population.<ref name="census">{{cite web |title=Illinois—Race and Hispanic Origin: 1800 to 1990 |publisher=U.S. Census Bureau |url=https://www.census.gov/population/www/documentation/twps0056/twps0056.html |archive-url=https://web.archive.org/web/20080725044857/http://www.census.gov/population/www/documentation/twps0056/twps0056.html |url-status=dead |archive-date=July 25, 2008}}</ref> Bolstered by continued [[History of immigration to the United States|immigration from southern and eastern Europe]], and by the African-American [[Great Migration (African American)|Great Migration]] from the South, Illinois grew and emerged as one of the most important states in the union. By the end of the century, the population had reached 12.4&nbsp;million.

The [[Century of Progress]] [[World's fair]] was held at Chicago in 1933. Oil strikes in [[Marion County, Illinois|Marion County]] and [[Crawford County, Illinois|Crawford County]] led to a boom in 1937, and by 1939, Illinois ranked fourth in U.S. oil production. Illinois manufactured 6.1 percent of total United States military armaments produced during [[World War&nbsp;II]], ranking seventh among the 48 states.<ref>{{cite book|last1=Peck| first1=Merton J.| author-link2=Frederic M. Scherer |last2=Scherer |first2=Frederic M. |title=The Weapons Acquisition Process: An Economic Analysis |year=1962 |publisher=Harvard Business School |page=111}}</ref> Chicago became an ocean port with the opening of the [[Saint Lawrence Seaway]] in 1959. The seaway and the [[Illinois Waterway]] connected Chicago to both the Mississippi River and the [[Atlantic Ocean]]. In 1960, [[Ray Kroc]] opened the first [[McDonald's]] franchise in [[Des Plaines, Illinois|Des Plaines]], which was demolished in 1984.<ref name=":0">{{Cite web |title=McDonald's Store No. 1 (Gone), Des Plaines, Illinois |url=https://www.roadsideamerica.com/story/11370 |access-date=2024-03-12 |website=RoadsideAmerica.com |language=en |archive-date=March 12, 2024 |archive-url=https://web.archive.org/web/20240312024737/https://www.roadsideamerica.com/story/11370 |url-status=live }}</ref> In 1985 a replica was built on the same site to recreate how the original one looked.<ref name=":0" /> Though this replica was demolished in 2017, due to repeated flooding of the building.<ref>{{Cite web |date=2014-02-27 |title=Des Plaines blames Mt. Prospect, Prospect Hts. for heightened flooding - DailyHerald.com |url=https://www.dailyherald.com/article/20130419/news/704199563/ |access-date=2024-03-12 |archive-url=https://web.archive.org/web/20140227181958/https://www.dailyherald.com/article/20130419/news/704199563/ |archive-date=February 27, 2014 }}</ref><ref>{{Cite web |last=Placek |first=Christopher |date=2017-11-20 |title=McDonald's plans to tear down Des Plaines replica restaurant |url=https://www.dailyherald.com/20171120/news/mcdonalds-plans-to-tear-down-des-plaines-replica-restaurant/ |access-date=2024-03-12 |website=Daily Herald |language=en-US |archive-date=March 12, 2024 |archive-url=https://web.archive.org/web/20240312024737/https://www.dailyherald.com/20171120/news/mcdonalds-plans-to-tear-down-des-plaines-replica-restaurant/ |url-status=live }}</ref>

Illinois had a prominent role in the emergence of the [[nuclear age]]. In 1942, as part of the [[Manhattan Project]], the [[Chicago Pile-1|University of Chicago]] conducted the first sustained [[nuclear chain reaction]]. In 1957, [[Argonne National Laboratory]], near [[Chicago]], activated the first experimental nuclear power generating system in the United States. By 1960, the first privately financed nuclear plant in the United States, [[Dresden Nuclear Power Plant|Dresden 1]], was dedicated near [[Morris, Illinois|Morris]]. In 1967, [[Fermilab]], a national nuclear research facility near [[Batavia, Illinois|Batavia]], opened a [[particle accelerator]], which was the world's largest for over 40 years. With eleven plants currently operating, Illinois leads all states in the amount of electricity generated from nuclear power.<ref>{{cite web |url=https://www.comed.com/sites/PartnersBusiness/Documents/EconomicDevelopmentFactSheet.pdf |title=ComEd and Electricity Related Messages for Economic Development |access-date=February 7, 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110708180209/https://www.comed.com/sites/PartnersBusiness/Documents/EconomicDevelopmentFactSheet.pdf |archive-date=July 8, 2011}}</ref><ref>{{cite web |url=https://www.comed.com/Documents/about-us/economic-development/ComEd_and_Electricity_Related_EconDev_Messages_-_January_2012.pdf |title=Home &#124; ComEd—An Exelon Company |publisher=ComEd |access-date=February 27, 2016 |url-status=dead |archive-url=https://web.archive.org/web/20130914144313/https://www.comed.com/Documents/about-us/economic-development/ComEd_and_Electricity_Related_EconDev_Messages_-_January_2012.pdf |archive-date=September 14, 2013}}</ref>

In 1961, Illinois became the first state in the nation to adopt the recommendation of the [[American Law Institute]] and pass a comprehensive criminal code revision that repealed the law against [[Sodomy laws in the United States|sodomy]]. The code also abrogated [[common law crime]]s and established an [[age of consent]] of 18.<ref>{{cite web |last=Painter |first=George |title=The History of Sodomy Laws in the United States: Illinois |url=http://www.glapn.org/sodomylaws/sensibilities/illinois.htm#fn73 |website=The Sensibilities of Our Forefathers |publisher=Gay & Lesbian Archives of the Pacific Northwest |access-date=January 12, 2012 |date=August 10, 2004 |archive-url=https://web.archive.org/web/20100515065329/http://www.glapn.org/sodomylaws/sensibilities/illinois.htm#fn73 |archive-date=May 15, 2010 |url-status=dead}}</ref> The state's [[Illinois Constitution|fourth constitution]] was adopted in 1970, replacing the 1870 document.<ref>{{cite journal |last1=Hillard |first1=James |title=The Illinois Constitution: A Primer |journal=Illinois Bar Journal |date=October 2008 |volume=96 |issue=10 |page=494 |url=https://www.isba.org/ibj/2008/10/theillinoisconstitutionaprimer |access-date=November 2, 2019 |archive-url=https://web.archive.org/web/20191102094526/https://www.isba.org/ibj/2008/10/theillinoisconstitutionaprimer |archive-date=November 2, 2019 |url-status=dead}}</ref>

The first [[Farm Aid]] concert was held in [[Champaign, Illinois|Champaign]] to benefit American farmers, in 1985. The worst [[upper Mississippi River]] flood of the century, the [[Great Flood of 1993]], inundated many towns and thousands of acres of farmland.<ref name="Biles" />

===21st century===
[[File:Jackson Avenue at Federal Plaza, Stay Home City of Chicago Ad.jpg|thumb|A COVID-19 safety message in the Chicago Loop]]
Illinois entered the 21st century under Republican Governor [[George Ryan]]. Near the end of his term in January 2003, following a string of high-profile exonerations, Ryan commuted all [[Capital punishment in Illinois|death sentences]] in the state.<ref>{{cite news |url =https://news.wttw.com/2020/09/24/former-illinois-gov-george-ryan-we-gotta-do-away-death-penalty |date=2020-09-24 | publisher=WTTW | access-date=2023-06-13 | title=Former Illinois Gov. George Ryan: 'We Gotta Do Away with the Death Penalty' | first=Evan | last=Garcia |archive-url=https://web.archive.org/web/20230614020343/https://news.wttw.com/2020/09/24/former-illinois-gov-george-ryan-we-gotta-do-away-death-penalty |archive-date=2023-06-14}}</ref>

The [[2002 Illinois gubernatorial election|2002 election]] brought Democrat [[Rod Blagojevich]] to the governor's mansion. It also brought future president [[Barack Obama]] into a committee leadership position in the Illinois Senate, where he drafted the [[Health Care Justice Act]], a forerunner of the [[Affordable Care Act]].<ref name="fight-tested">{{cite news |url=https://www.washingtonpost.com/wp-dyn/content/article/2009/09/08/AR2009090803790.html?nav=rss_email/components  |title=In Illinois, a Similar Fight Tested a Future President  |first1=Michael D.  |last1=Shear |first2=Ceci |last2=Connolly |newspaper=Washington Post |date=2009-09-09 |archive-url=https://web.archive.org/web/20121108191922/http://www.washingtonpost.com/wp-dyn/content/article/2009/09/08/AR2009090803790.html?nav=rss_email/components |archive-date=2012-11-08 }}</ref> Obama's election to the presidency in Blagojevich's second term set off a chain of events culminating in [[Rod Blagojevich corruption charges|Blagojevich's impeachment]], trial, and subsequent criminal conviction and imprisonment, making Blagojevich the second consecutive Illinois governor to be convicted on federal corruption charges.<ref>{{cite news |url=https://abc7chicago.com/illinois-governors-in-jail-jailed-who-did-time-served/5944787/ |publisher=ABC 7 Chicago |title=4 Illinois governors have served time in prison |date=2020-02-19 |access-date=2023-06-13 |archive-url=https://web.archive.org/web/20230909070738/https://abc7chicago.com/illinois-governors-in-jail-jailed-who-did-time-served/5944787/ |archive-date=2023-09-09}}</ref>

Blagojevich's replacement [[Pat Quinn (politician)|Pat Quinn]] was defeated by Republican [[Bruce Rauner]] in the [[2014 Illinois gubernatorial election|2014 election]]. Disagreements between the governor and legislature over budgetary policy led to the [[Illinois Budget Impasse]], a 793-day period stretching from 2015 to 2018 in which the state had no budget and struggled to pay its bills.<ref>{{Cite news | publisher = WTTW | title = J.B. Pritzker Takes Oath as Illinois' 43rd Governor | author-first = Amanda | author-last = Vinicky | url = https://news.wttw.com/2019/01/14/jb-pritzker-takes-oath-illinois-43rd-governor | date = 2019-01-14 | access-date = 2023-06-13 | archive-date = June 14, 2023 | archive-url = https://web.archive.org/web/20230614020307/https://news.wttw.com/2019/01/14/jb-pritzker-takes-oath-illinois-43rd-governor | url-status = live }}</ref>

On August 28, 2017, Rauner signed a bill into law that prohibited state and local police from arresting anyone solely due to their immigration status or due to federal detainers.<ref>{{cite web |last1=Bernal |first1=Rafael |title=Illinois Governor Signs Immigration, Automatic Voter Registration Measures |url=https://thehill.com/latino/348283-illinois-governor-signs-immigration-automatic-voter-registration-measures/ |date=August 28, 2017 |work=[[The Hill (newspaper)|The Hill]] | access-date=September 3, 2019 | archive-url=https://web.archive.org/web/20190903111831/https://thehill.com/latino/348283-illinois-governor-signs-immigration-automatic-voter-registration-measures | archive-date=September 3, 2019 | url-status=live}}</ref><ref>{{cite web |last1=Tareen |first1=Sophia |title=Governor Signs Law Limiting Illinois Police on Immigration |url=https://abcnews.go.com/Politics/wireStory/governor-signs-law-limiting-illinois-police-immigration-49472288 |date=August 28, 2017 |publisher=[[ABC News (United States)|ABC News]] (from the [[Associated Press]]) | access-date=September 3, 2019 | archive-url=https://web.archive.org/web/20170910125132/https://abcnews.go.com/Politics/wireStory/governor-signs-law-limiting-illinois-police-immigration-49472288 | archive-date=September 10, 2017 | url-status=dead}}</ref> Some fellow Republicans criticized Rauner for his action, claiming the bill made Illinois a [[Sanctuary city|sanctuary state]].<ref>{{cite web |last1=Singman |first1=Brooke |title=GOP Gov. Rauner Accused of Making Illinois a 'Sanctuary State' with New Law |url=https://www.foxnews.com/politics/gop-gov-rauner-accused-of-making-illinois-a-sanctuary-state-with-new-law/ |date=August 28, 2017 |publisher=[[Fox News]] | access-date=September 3, 2019 | archive-url=https://web.archive.org/web/20180709204706/http://www.foxnews.com/politics/2017/08/28/gop-gov-rauner-accused-making-illinois-sanctuary-state-with-new-law.html | archive-date=July 9, 2018 | url-status=live}}</ref>

In the [[2018 Illinois gubernatorial election|2018 election]], Rauner was replaced by [[J. B. Pritzker]], returning the state government to a Democratic [[government trifecta|trifecta]].<ref>{{Cite news | via = Virgin Islands Daily News | publisher = Associated Press | title = GOP, Democrats splitting governor's races in key states | author-first = David A. | author-last = Lieb | date = 2018-11-07 | access-date = 2023-06-13 | url = http://www.virginislandsdailynews.com/ap/gop-democrats-splitting-governors-races-in-key-states/article_5341ede1-c111-579e-862d-089aa4bd4b89.html | archive-date = June 14, 2023 | archive-url = https://web.archive.org/web/20230614020258/http://www.virginislandsdailynews.com/ap/gop-democrats-splitting-governors-races-in-key-states/article_5341ede1-c111-579e-862d-089aa4bd4b89.html | url-status = live }}</ref> In January 2020 the state [[Illinois Cannabis Regulation and Tax Act|legalized marijuana]].<ref>{{Cite news | url = https://www.npr.org/2020/01/01/792681442/6-new-state-laws-you-should-know-about-in-2020 | access-date = 2023-06-13 | date = 2020-01-01 | title = 6 New State Laws You Should Know About In 2020 | author-first = Acacia | author-last = Squires | archive-date = November 11, 2022 | archive-url = https://web.archive.org/web/20221111043153/https://www.npr.org/2020/01/01/792681442/6-new-state-laws-you-should-know-about-in-2020 | url-status = live }}</ref> On March 9, 2020, Pritzker issued a disaster proclamation due to the [[COVID-19 pandemic in Illinois|COVID-19 pandemic]]. He ended the state of emergency in May 2023.<ref>{{cite news | title = COVID-19 public health emergency ends Thursday in US, Illinois | publisher = ABC 7 Chicago | author-first = Diane | author-last = Pathieu | date = 2023-05-11 | url = https://abc7chicago.com/covid-19-public-health-emergency-illinois-test-vaccine/13233372/ | access-date = 2023-06-13 | archive-date = June 14, 2023 | archive-url = https://web.archive.org/web/20230614020258/https://abc7chicago.com/covid-19-public-health-emergency-illinois-test-vaccine/13233372/ | url-status = live }}</ref>