title: Henry B. Clarke House
context: Clarke House may have been modeled on the home of William B. Ogden.[3] The Clarke house is often described as the oldest surviving house in Chicago,[4] 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.)[5] The Clarke House was designated a Chicago Landmark on October 14, 1970.[6]  It was added to the National Register of Historic Places on May 6, 1971.
question: What is the oldest building in Chicago?
answers: Clarke House