Carroll County Illinois (Historic Districts) has 2 places on the National Register of Historic Places including 1 place of Statewide significance. Significant places include Mississippi Palisades State Park, Mount Carroll Historic District.
Some of the country's most noteable architects helped create the Carroll County places including D.B. Lawrence and C. Harfagifer. Prominent architectural styles found in Carroll Country are Colonial Revival, Italianate and Prairie School.