The DeLong House was added to the National Register of Historic Places in 1984. In the years since, the Chapman Museum has added an exhibition gallery, climate controlled collections storage, a research room, multi-purpose classroom, and a museum shop.
In 1984, the DeLong House was listed on the National Register of Historic Places. Over time, the Chapman Museum expanded by incorporating an exhibition gallery, climate-controlled storage area for artifacts, a research room, a multifunctional classroom, and a retail space.