Hancock County Illinois (Historic Districts) has 4 places on the National Register of Historic Places including 1 place of National significance and 1 place of Statewide significance. Significant places include Nauvoo Historic District and Warsaw Historic District, Carthage Courthouse Square Historic District, LaHarpe Historic District.
The famous person Joseph Smith is associated with one of more of the Hancock County historic places.
Some of the country's most noteable architects helped create the Hancock County places including George W. & Son Payne. Prominent architectural styles found in Hancock Country are Italianate, Beaux Arts and Federal.