Rockcliffe Mansion in Hannibal, Missouri, was built in 1898 by lumber magnate John J. Cruikshank, Jr., as a 30-room private residence.
It was designed in the Georgian Revival style by the St. Louis firm of Barnett, Haynes & Barnett, and is in the National Register of Historic Places.

It is currently privately owned and functions as a museum and a B&B.

See http://en.wikipedia.org/wiki/Rockcliffe_Mansion, and, for tours and reservations, http://www.rockcliffemansion.com.