Illinois Counties
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Illinois Counties

There are one hundred and two counties in Illinois. St. Clair County was the first county established in what is today Illinois. Most counties in Illinois were named after early American leaders, especially of the American Revolutionary War, as well as soldiers from the Battle of Tippecanoe and the War of 1812.
 

Illinois Counties: History and Information

Find a brief history of Illinois CountiesBrief history of Illinois Counties: Flags of Our Nation

The State of Illinois is the 21st to be admitted to the Union. Illinois is the most populous and demographically diverse Midwestern state and the fifth most populous in the nation.

There are 102 counties in the state of Illinois. Most counties in Illinois were named after early American leaders, especially of the American Revolutionary War, as well as soldiers from the Battle of Tippecanoe and the War of 1812. Some are named after natural features or counties in other states. Some are named for early Illinois leaders. Two counties are named for Native American tribes, and one bears the name of a plant used as a food source by Native Americans.

While it does have a city, Illinois does not have a Lincoln County named after its favorite son, Abraham Lincoln; it does, however, have a Douglas County (founded 1859) named after his political rival Stephen A. Douglas. It also has Calhoun County (founded 1825), named after John C. Calhoun, outspoken for his southern views in the years preceding the American Civil War. Several of the counties are named after Southerners, reflecting the fact that Illinois was for a short time part of Virginia, and settled in its early years by many Southerners. No counties are named after Northern heroes of the Civil War, mainly because the counties were all named before that war. The state does have a Lee County named after the family of Robert E. Lee, who at one time served in Illinois. Illinois also has a singular distinction of having two counties named after the same person, New York governor, DeWitt Clinton.

Find a brief history of Illinois Counties
County 2000
Population
Square
Miles
County Seat Created
Adams County 68,277 857 Quincy 1825
Alexander County 9,590 236 Cairo 1819
Bond County 17,633 380 Greenville 1817
Boone County 41,786 281 Belvidere 1837
Brown County 6,950 306 Mount Sterling 1839
Bureau County 35,503 869 Princeton 1837
Calhoun County 5,084 254 Hardin 1825
Carroll County 16,674 444 Mount Carroll 1839
Cass County 13,695 376 Virginia 1837
Champaign County 179,669 997 Urbana 1833
Christian County 35,372 709 Taylorville 1839
Clark County 17,008 502 Marshall 1819
Clay County 14,560 469 Louisville 1824
Clinton County 35,535 474 Carlyle 1824
Coles County 53,196 508 Charleston 1830
Cook County 5,376,741 946 Chicago 1831
Crawford County 20,452 444 Robinson 1816
Cumberland County 11,253 346 Toledo 1843
De Witt County 16,798 398 Clinton 1839
DeKalb County 88,969 634 Sycamore 1837
Douglas County 19,922 417 Tuscola 1859
DuPage County 904,161 334 Wheaton 1939
Edgar County 19,704 624 Paris 1823
Edwards County 6,971 222 Albion 1814
Effingham County 34,264 479 Effingham 1831
Fayette County 21,802 716 Vandalia 1821
Ford County 14,241 486 Paxton 1859
Franklin County 39,018 412 Benton
Fulton County 38,250 866 Lewistown 1823
Gallatin County 6,445 324 Shawneetown 1812
Greene County 14,761 543 Carrollton 1821
Grundy County 37,535 420 Morris 1841
Hamilton County 8,621 435 McLeansboro 1821
Hancock County 20,121 795 Carthage 1825
Hardin County 4,800 178 Elizabethtown 1839
Henderson County 8,213 379 Oquawka 1841
Henry County 51,020 823 Cambridge 1825
Iroquois County 31,334 1,116 Watseka 1833
Jackson County 59,612 588 Murphysboro 1816
Jasper County 10,117 494 Newton 1831
Jefferson County 40,045 571 Mount Vernon 1819
Jersey County 21,668 369 Jerseyville 1839
Jo Daviess County 22,289 601 Galena 1827
Johnson County 12,878 346 Vienna 1812
Kane County 404,119 521 Geneva 1836
Kankakee County 103,833 678 Kankakee 1853
Kendall County 54,544 321 Yorkville 1841
Knox County 55,836 716 Galesburg 1825
Lake County 644,356 448 Waukegan 1839
LaSalle County 111,509 1,135 Ottawa 1831
Lawrence County 15,452 372 Lawrenceville 1821
Lee County 36,062 725 Dixon 1839
Livingston County 39,678 1,044 Pontiac 1837
Logan County 31,183 618 Lincoln 1839
Macon County 114,706 581 Decatur 1829
Macoupin County 49,019 864 Carlinville 1829
Madison County 258,941 725 Edwardsville 1812
Marion County 41,691 572 Salem 1823
Marshall County 13,180 386 Lacon 1839
Mason County 16,038 539 Havana 1841
Massac County 15,161 239 Metropolis 1843
McDonough County 32,913 589 Macomb 1826
McHenry County 260,077 604 Woodstock 1836
McLean County 150,433 1,184 Bloomington 1830
Menard County 12,486 314 Petersburg 1839
Mercer County 16,957 561 Aledo 1825
Monroe County 27,619 388 Waterloo 1816
Montgomery County 30,652 704 Hillsboro 1821
Morgan County 36,616 569 Jacksonville 1823
Moultrie County 14,287 336 Sullivan 1843
Ogle County 51,032 759 Oregon 1836
Peoria County 183,433 620 Peoria 1825
Perry County 23,094 441 Pinckneyville 1827
Piatt County 16,365 440 Monticello 1841
Pike County 17,384 830 Pittsfield 1821
Pope County 4,413 371 Golconda 1816
Pulaski County 7,348 201 Mound City 1843
Putnam County 6,086 160 Hennepin 1825
Randolph County 33,893 578 Chester 1795
Richland County 16,149 360 Olney 1841
Rock Island County 149,374 427 Rock Island 1831
Saline County 26,733 383 Harrisburg 1847
Sangamon County 188,951 868 Springfield 1821
Schuyler County 7,189 437 Rushville 1825
Scott County 5,537 251 Winchester 1839
Shelby County 22,893 759 Shelbyville 1827
St. Clair County 256,082 664 Belleville 1790
Stark County 6,332 288 Toulon 1839
Stephenson County 48,979 564 Freeport 1837
Tazewell County 128,485 649 Pekin 1827
Union County 18,293 416 Jonesboro
Vermilion County 83,919 899 Danville 1826
Wabash County 12,937 224 Mount Carmel 1824
Warren County 18,735 543 Monmouth 1825
Washington County 15,148 563 Nashville
Wayne County 17,151 714 Fairfield 1819
White County 15,371 495 Carmi 1815
Whiteside County 60,653 685 Morrison 1836
Will County 502,266 837 Joliet 1836
Williamson County 61,296 424 Marion 1839
Winnebago County 278,418 514 Rockford 1836
Woodford County 35,469 528 Eureka 1841


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