Counties in Illinois

1. Knox (State: Illinois Population: 40,501)
2. DuPage (State: Illinois Population: 738,036)
3. Edwards (State: Illinois Population: 4,659)
4. Mercer (State: Illinois Population: 3,613)
5. McHenry (State: Illinois Population: 188,040)
6. Rock Island (State: Illinois Population: 116,954)
7. Union (State: Illinois Population: 8,105)
8. Lake (State: Illinois Population: 545,357)
9. Christian (State: Illinois Population: 21,946)
10. Menard (State: Illinois Population: 1,726)
11. Logan (State: Illinois Population: 18,719)
12. Sangamon (State: Illinois Population: 141,291)
13. Kane (State: Illinois Population: 386,814)
14. Pike (State: Illinois Population: 6,837)
15. Peoria (State: Illinois Population: 145,957)
16. Will (State: Illinois Population: 314,012)
17. Piatt (State: Illinois Population: 8,358)
18. Macoupin (State: Illinois Population: 27,548)
19. Moultrie (State: Illinois Population: 6,835)
20. McLean (State: Illinois Population: 123,818)
21. Macon (State: Illinois Population: 97,126)
22. Kankakee (State: Illinois Population: 70,357)
23. Massac (State: Illinois Population: 7,536)
24. McDonough (State: Illinois Population: 23,272)
25. Ogle (State: Illinois Population: 25,566)
26. Alexander (State: Illinois Population: 3,632)
27. Champaign (State: Illinois Population: 141,217)
28. Coles (State: Illinois Population: 39,330)
29. Edgar (State: Illinois Population: 10,395)
30. Iroquois (State: Illinois Population: 12,819)
31. De Witt (State: Illinois Population: 9,540)
32. Bureau (State: Illinois Population: 9,842)
33. Jo Daviess (State: Illinois Population: 8,877)
34. Whiteside (State: Illinois Population: 36,971)
35. Effingham (State: Illinois Population: 13,943)
36. Woodford (State: Illinois Population: 17,686)
37. Stephenson (State: Illinois Population: 29,330)
38. Bond (State: Illinois Population: 6,955)
39. Mason (State: Illinois Population: 7,868)
40. Jersey (State: Illinois Population: 7,984)
41. Wabash (State: Illinois Population: 7,982)