Carnahan Hall was designed in the neoclassical style by Jerome B. Legg of St. Louis and completed in 1902. It was initially built as the Science Building, and later became the Social Science Building. A chapel was once housed inside it and was used for daily prayer. The Missouri state seal is in cast bronze relief above the front entrances. It is the oldest standing building on campus and underwent a major renovation between 1994 and 1998. During the renovation the entire interior was removed from the masonry shell, and rebuilt with state of the art technology without diminishing the historic fabric of the building’s exterior. Upon completion of the project, the building was rededicated as Carnahan Hall in honor of longtime Southeast Missouri congressman and U.S. ambassador A.S.J. Carnahan of Ellsinore MO.