Johnson County Nebraska has 5 places on the National Register of Historic Places including 4 places of Statewide significance. Significant places include Johnson County Courthouse, Keim Stone Arch Bridge, Tecumseh Historic District and Tecumseh Opera House and Townsend, George, House.
Some of the country's most noteable architects helped create the Johnson County places including Keim Cement Co., W.L. Dunlap, William Gray and Edgar W. Cook. Prominent architectural styles found in Johnson Country are Classical Revival, Greek Revival and Late Victorian.