Statement of Significance (as of designation - December 9, 1997):
Dating from the beginning of the nineteenth century, Riversdale is one of the last of Maryland's great five-part Palladian mansions. Of stuccoed brick, it was built for Belgian emigree Henri Joseph Stier, and was for a time the repository of the Stier family's collection of Old World master paintings, the most outstanding collection of its type in the country at the time. Riversdale is also significant for its association with Charles Benedict Calvert, Stier's grandson. Calvert helped establish the Maryland Agricultural College on part of the extensive Riversdale acreage, and was instrumental in the establishment of the federal-level Bureau of Agriculture, now the U.S. Department of Agriculture. Riversdale, now restored, is open to the public as a historic house museum.