Illinois counties quiz

The 102 counties in the quiz

They’re the 102 counties of Illinois, as counted by the US Census Bureau. The state capital, Springfield, is in Sangamon County.

How to play

In Point mode we name a county and you tap it on the map; in Type mode one lights up and you type its name (accents don’t matter); and in Time trial you get 6 seconds per question. If you miss, we show you where it was, which way it lies and a hint drawn from the data: its size rank and its neighbors.

Each game has 10, 20 or all the questions, and at the end you can practice just the ones you missed. Your best score for each mode is saved in this browser only: neither we nor anyone else can see it, and there’s no sign-up.

The hardest ones

The smallest counties are the hardest, since they barely show on the map: Putnam (160 sq mi), Hardin (177 sq mi), and Pulaski (199 sq mi). Zoom in with the buttons or two fingers to tap them.

And watch out for look-alike names: Macon and Mason.

Tips to learn them

• The 12 counties bordering Missouri trace that border on the map: Adams, Alexander, Calhoun, Hancock, Jackson, Jersey, Madison, Monroe, Pike, Randolph, St. Clair, and Union.
• Only 2 of the 102 counties have a Great Lakes shoreline: find them first along the edge of the map.
• LaSalle has the most neighbors: it borders 9 counties. Once you place it, you have a landmark for many more.
• Cook is the most populous (5,194,625 people in 2025) and, together with DuPage and Lake, is home to 54% of Illinois’s people.

Playing in class

If you teach in Illinois, start with your school’s county and its neighbors and add a few each day. Otherwise, it’s a good way to get to know the state before studying it.

With the Challenge your class link, everyone gets the same questions in the same order, with no accounts or passwords, and each student sees their own score, time and streak. To practice on paper, there’s a printable worksheet of the same map with an answer key.

List of all 102 counties

1. Adams pop. 64,267
2. Alexander pop. 4,570
3. Bond pop. 16,959
4. Boone pop. 53,568
5. Brown pop. 6,401
6. Bureau pop. 32,510
7. Calhoun pop. 4,300
8. Carroll pop. 15,419
9. Cass pop. 12,463
10. Champaign pop. 209,972
11. Christian pop. 33,443
12. Clark pop. 15,114
13. Clay pop. 12,793
14. Clinton pop. 37,128
15. Coles pop. 46,607
16. Cook pop. 5,194,625
17. Crawford pop. 18,648
18. Cumberland pop. 10,208
19. De Witt pop. 15,118
20. DeKalb pop. 101,835
21. Douglas pop. 19,880
22. DuPage pop. 934,298
23. Edgar pop. 16,323
24. Edwards pop. 5,898
25. Effingham pop. 34,519
26. Fayette pop. 20,790
27. Ford pop. 13,216
28. Franklin pop. 36,916
29. Fulton pop. 32,901
30. Gallatin pop. 4,616
31. Greene pop. 11,313
32. Grundy pop. 54,052
33. Hamilton pop. 7,859
34. Hancock pop. 16,803
35. Hardin pop. 3,588
36. Henderson pop. 5,984
37. Henry pop. 48,095
38. Iroquois pop. 26,150
39. Jackson pop. 52,501
40. Jasper pop. 9,032
41. Jefferson pop. 36,147
42. Jersey pop. 21,160
43. Jo Daviess pop. 21,594
44. Johnson pop. 13,363
45. Kane pop. 525,757
46. Kankakee pop. 105,525
47. Kendall pop. 145,470
48. Knox pop. 47,767
49. Lake pop. 719,339
50. LaSalle pop. 107,773
51. Lawrence pop. 13,790
52. Lee pop. 32,914
53. Livingston pop. 35,057
54. Logan pop. 27,182
55. Macon pop. 99,300
56. Macoupin pop. 43,748
57. Madison pop. 263,110
58. Marion pop. 36,382
59. Marshall pop. 11,473
60. Mason pop. 12,411
61. Massac pop. 13,502
62. McDonough pop. 25,916
63. McHenry pop. 317,751
64. McLean pop. 171,419
65. Menard pop. 11,863
66. Mercer pop. 15,229
67. Monroe pop. 34,840
68. Montgomery pop. 28,076
69. Morgan pop. 32,515
70. Moultrie pop. 14,371
71. Ogle pop. 51,399
72. Peoria pop. 178,553
73. Perry pop. 20,160
74. Piatt pop. 16,791
75. Pike pop. 14,231
76. Pope pop. 3,672
77. Pulaski pop. 4,820
78. Putnam pop. 5,619
79. Randolph pop. 29,921
80. Richland pop. 15,219
81. Rock Island pop. 141,869
82. Saline pop. 22,772
83. Sangamon pop. 194,170
84. Schuyler pop. 6,657
85. Scott pop. 4,866
86. Shelby pop. 20,576
87. St. Clair pop. 250,708
88. Stark pop. 5,319
89. Stephenson pop. 43,220
90. Tazewell pop. 130,049
91. Union pop. 16,656
92. Vermilion pop. 71,259
93. Wabash pop. 10,907
94. Warren pop. 16,222
95. Washington pop. 13,564
96. Wayne pop. 15,882
97. White pop. 13,250
98. Whiteside pop. 54,121
99. Will pop. 712,253
100. Williamson pop. 67,225
101. Winnebago pop. 283,674
102. Woodford pop. 38,111