ILGenWeb Main Page ** Clickable County Map
IL City/Town ListTownship/County Lookup
| County Name | Map | Date of Formation | Parent County | County Seat | County Coordinators |
|---|---|---|---|---|---|
| Adams |  | 1825 | Pike | Quincy | Dennis Partridge |
| Alexander |  | 1819 | Union | Cairo | Norma Hass and Deborah Cox |
| Bond |  | 1818 | Madison | Greenville | Norma Hass |
| Boone |  | 1836 | Winnebago | Belvidere | Joe Markovich |
| Brown |  | 1837 | Schuyler | Mount Sterling | Dennis Partridge |
| Bureau |  | 1837 | Putnam | Princeton | ADOPTABLE |
| Calhoun |  | 1825 | Pike | Hardin | ADOPTABLE |
| Carroll |  | 1839 | Jo Daviess | Mount Carroll | ADOPTABLE |
| Cass |  | 1837 | Morgan | Virginia | Rebecca Maloney |
| Champaign |  | 1833 | Vermilion | Urbana | ADOPTABLE |
| Christian |  | 1839 | Dane (Montgomery, Sangamon, Shelby) | Taylorville | Morgan Edward Johnson |
| Clark |  | 1819 | Crawford | Marshall | Joy Fisher |
| Clay |  | 1824 | Crawford, Fayette, Wayne | Louisville | ADOPTABLE |
| Clinton |  | 1824 | Bond, Washington | Carlyle | Larry Jones |
| Coles |  | 1830 | Clark, Edgar | Charleston | ADOPTABLE |
| Cook |  | 1831 | Putnam | Chicago | Dennis Partridge |
| Crawford |  | 1816 * | Edwards (IT) | Robinson | Mary Kozy |
| Cumberland |  | 1843 | Coles | Toledo | Michael L. Hebert |
| Dane | . | 1839 | Montgomery, Sangamon, Shelby | Extinct-1840 now Christian | See Christian County |
| DeKalb |  | 1837 | Kane | Sycamore | ADOPTABLE |
| DeWitt |  | 1839 | Macon, McLean | Clinton | Pat Geary |
| Douglas |  | 1859 | Coles | Tuscola | ADOPTABLE |
| DuPage |  | 1839 | Cook | Wheaton | ADOPTABLE |
| Edgar |  | 1823 | Clark | Paris | Maggie Stewart & Joy Fisher |
| Edwards |  | 1814* | Gallatin, Madison (IT) | Albion | ADOPTABLE |
| Effingham |  | 1831 | Crawford, Fayette | Effingham | ADOPTABLE |
| Fayette |  | 1821 | Bond, Clark, Crawford, Jefferson | Vandalia | Penny Lewis |
| Ford |  | 1859 | unorganized (Vermilion) | Paxton | ADOPTABLE |
| Franklin |  | 1818* | Gallatin, White | Benton | Susan Dorris |
| Fulton |  | 1823 | Pike | Lewistown | Julie Tarr |
| Gallatin |  | 1812* | Randolph (IT) | Shawneetown | Susan Dorris |
| Greene |  | 1821 | Madison | Carrollton | ADOPTABLE |
| Grundy |  | 1841 | LaSalle | Morris | Dennis Partridge |
| Hamilton |  | 1821 | White | McLeansboro | Michael L. Hebert |
| Hancock |  | 1825 | Pike | Carthage | ADOPTABLE |
| Hardin |  | 1839 | Gallatin, Pope | Elizabethtown | ADOPTABLE |
| Henderson |  | 1841 | Warren | Oquawka | Joe Markovich |
| Henry |  | 1825 | unorganized (Fulton) | Cambridge | Joe Markovich |
| Iroquois |  | 1833 | unorganized (Vermilion) | Watseka | Concetta Phillipps |
| Jackson |  | 1816* | Johnson, Randolph | Murphysboro | Norma Hass and Melissa McCord |
| Jasper |  | 1831 | Clay, Crawford | Newton | ADOPTABLE |
| Jefferson |  | 1819 | Edwards, White | Mt. Vernon | Sandy Bauer |
| Jersey |  | 1839 | Greene | Jerseyville | Dennis Partridge |
| JoDaviess |  | 1827 | Henry, Putnam | Galena | ADOPTABLE |
| Johnson |  | 1812* | Randolph (IT) | Vienna | Norma Hass and Jackie Webb |
| Kane |  | 1836 | unorganized (LaSalle), Cook | Geneva | ADOPTABLE |
| Kankakee |  | 1853 | Ford, Iroquois, Will | Kankakee | Concetta Phillipps |
| Kendall |  | 1841 | LaSalle, Kane | Yorkville | ADOPTABLE |
| Knox |  | 1825 | unorganized (Fulton), Fulton, Henry | Galesburg | ADOPTABLE |
| Lake |  | 1839 | McHenry | Waukegan | Joe Markovich |
| LaSalle |  | 1831 | Putnam, unorganized (Tazewell) | Ottawa | ADOPTABLE |
| Lawrence |  | 1821 | Crawford, Edwards | Lawrenceville | Mary Kozy |
| Lee |  | 1839 | Ogle | Dixon | Joe Markovich |
| Livingston |  | 1837 | LaSalle, McLean, unorganized (Vermilion?) | Pontiac | ADOPTABLE |
| Logan |  | 1839 | McLean, Sangamon, Tazewell | Lincoln | Cheryl Rothwell |
| Macon |  | 1829 | unorganized (Shelby) | Decatur | Cheryl Rothwell |
| Macoupin |  | 1829 | unorganized (Greene), Madison | Carlinville | Norma Hass |
| Madison |  | 1812* | St. Clair (IT) | Edwardsville | Bev Bauser |
| Marion |  | 1823 | Fayette, Jefferson | Salem | ADOPTABLE |
| Marshall |  | 1839 | Putnam, LaSalle | Lacon | ADOPTABLE |
| Mason |  | 1841 | Menard, Tazewell | Havana | ADOPTABLE |
| Massac |  | 1843 | Johnson, Pope | Metropolis | Susan Dorris |
| McDonough |  | 1826 | Schuyler | Macomb | ADOPTABLE |
| McHenry |  | 1836 | Cook, unorganized (LaSalle) | Woodstock | Joe Markovich |
| McLean |  | 1830 | Tazewell, unorganized (Tazewell) | Bloomington | Carol Genung |
| Menard |  | 1839 | Sangamon | Petersburg | ADOPTABLE |
| Mercer |  | 1825 | unorganized (Pike) | Aledo | Joe Markovich |
| Monroe |  | 1816* | Randolph, St. Clair | Waterloo | Dennis Partridge |
| Montgomery |  | 1821 | Bond, Madison | Hillsboro | ADOPTABLE |
| Morgan |  | 1823 | unorganized (Greene), Sangamon | Jacksonville | Dennis Partridge |
| Moultrie |  | 1843 | Macon, Shelby | Sullivan | ADOPTABLE |
| Ogle |  | 1836 | Jo Daviess, unorganized (LaSalle) | Oregon | ADOPTABLE |
| Peoria |  | 1825 | Fulton, unorganized (Fulton) | Peoria | ADOPTABLE |
| Perry |  | 1827 | Jackson, Randolph | Pickneyville | ADOPTABLE |
| Piatt |  | 1841 | DeWitt, Macon | Monticello | Dee Lund |
| Pike |  | 1821 | Madison | Pittsfield | ADOPTABLE |
| Pope |  | 1816* | Gallatin, Johnson | Golconda | Ginger Hayes |
| Pulaski |  | 1843 | Alexander, Johnson | Mound City | Norma Hass and Deborah Cox |
| Putnam |  | 1825 | unorganized (Edgar, Fulton) | Hennepin | ADOPTABLE |
| Randolph |  | 1795* | St. Clair, Northwest Territory | Chester | Dennis Partridge |
| Richland |  | 1841 | Clay, Lawrence | Olney | ADOPTABLE |
| Rock Island |  | 1831 | Jo Daviess | Rock Island | Joe Markovich |
| Saline |  | 1847 | Gallatin | Harrisburg | Susan Dorris |
| Sangamon |  | 1821 | Bond, Madison | Springfield | Michael King |
| Schuyler |  | 1825 | Pike, unorganized (Pike) | Rushville | Dennis Partridge |
| Scott |  | 1839 | Morgan | Winchester | ADOPTABLE |
| Shelby |  | 1827 | Fayette | Shelbyville | ADOPTABLE |
| Stark |  | 1839 | Knox, Putnam | Toulon | ADOPTABLE |
| St. Clair |  | 1790* | Northwest Territory | Belleville | Diane Walsh |
| Stephenson |  | 1837 | Jo Daviess, Winnebago | Freeport | Joe Markovich |
| Tazewell |  | 1827 | unorganized (Peoria), Fayette | Pekin | Joe Markovich |
| Union |  | 1818 * | Johnson, Jackson | Jonesboro | Norma Hass and Melissa McCord |
| Vermilion |  | 1826 | unorganized (Edgar) | Danville | Joe Markovich |
| Wabash |  | 1824 | Edwards | Mount Carmel | ADOPTABLE |
| Warren |  | 1825 | unorganized (Pike) | Monmouth | ADOPTABLE |
| Washington |  | 1818* | St. Clair | Nashville | ADOPTABLE |
| Wayne |  | 1819 | Edwards | Fairfield | Sandy Bauer |
| White |  | 1815* | Madison (IT) | Carmi | Cindy Birk-Conley |
| Whiteside |  | 1836 | Jo Daviess, Henry | Morrison | Joe Markovich |
| Will |  | 1836 | Cook, Iroquois | Joliet | Dennis Partridge |
| Williamson |  | 1839 | Franklin | Marion | Susan Dorris |
| Winnebago |  | 1836 | JoDaviess, unorganized (LaSalle) | Rockford | Joe Markovich |
| Woodford |  | 1841 | McLean, Tazewell | Eureka | Carol Genung |
(IT) Illinois Territory