| Carroll County Illinois Cities/Towns - Chadwick, Elkhorn Grove, Fair Haven, Lanark, Milledgeville, Mount Carroll (County Seat), Savanna, Shannon, Thomson |
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Your Ad Here Carroll County is a county located in the U.S. state of Illinois. As of the 2000 census, the population was 16,674. Its county seat is Mount Carroll. History Carroll County was formed in 1839. The County is named for Charles Carroll who signed the Declaration of Independence. Carroll, who died in 1832 was the last signer to die. ![]() |