Henry B. Clarke House
Clarke House may have been modeled on the home of William B. Ogden. The Clarke house is often described as the oldest surviving house in Chicago, although part of the Noble-Seymour-Crippen House in the Norwood Park neighborhood was built in 1833. (However, Norwood Park was not annexed to Chicago until 1893.) The Clarke House was designated a Chicago Landmark on October 14, 1970. It was added to the National Register of Historic Places on May 6, 1971.
Elgin, Illinois
The Elgin Public Museum at Lords Park was the oldest building in Illinois built expressly as a museum that was still serving that purpose.