4811, Riverdale Road, Riverdale, Prince Georges County
Riversdale was planned in 1801 by Baron de Stier to resemble his Belgian home, Chateau du Mick. Only the central portion was built by de Stier, the hyphens and wings having been added c. 1830 by his son-in-law, George Calvert. The building is a large-scale late Georgian mansion with superior Federal interior. Both facades of the 7-bay by 4-bay central block are divided into three nearly equal sections, the center three bays of both being recessed to relieve the otherwise massive surfaces. A Doric portico gives access to the central door with its flanking windows. On north and south, both flanking surfaces contain two windows on each story slightly wider than the central windows. First floor windows are 9/9 sash while those on the second floor are 6/9. The south portico lacks the pediment found on the north side of the house, but instead of a door, there are three floor-length arched windows with flanking pilasters. During the 20th century, the entire house, including its water table and belt course, was stuccoed over the original brick. A hipped roof with "kick" at the eaves covers the main block. Its cornice has large mutule-like modillions. Flanking the late-19th century belvedere are two small interior chimneys, the east chimney being purely decorative. On the extreme east and west sides of the main block are deep narrow chimney stacks which service the hyphen fireplaces as well as those of the main block. One-bay hyphens, 1 1/2 stories in height, hold a door with traceried fanlight surmounted by a small two-light window on the north elevation. The flanking wings are one bay wide, with a shallow gable-front and pediment with dentiled cornice and raking cornice. A single 9/9 sash window pierces the north facade, with two small half-round windows above the window of the east wing. Wings are three bays deep, consisting of a central entrance flanked by 6/6 sash window openings, and three 3/3 sash windows above. The west facade door is surmounted by a traceried fanlight, while the east door is covered by a walkway connecting it to the dependency to the east. The south facade of the wings and hyphens are nearly flush with each other, and each contains a 6/6 sash window on each floor.
Riversdale's architectural significance derives from its role as one of the best late Georgian, five-part houses in Maryland. The Federal interior is of such high quality as to support the local tradition that attributes the design to William Thornton, architect of the Capitol. However, the available information on Thornton does not support the tradition. The historical significance of Riversdale rests with its builder, Henri Joseph the Baron de Stier, and his son-in-law George Calvert, who inherited the property. In 1794 de Stier immigrated to the United States from Belgium, which the French army had occupied. He lived in Anne Arundel County and in the Brice House in Annapolis immediately before building Riversdale, which he modeled after one of his European house. In 1799, de Stier's daughter married George Calvert, a descendant of the Lords Baltimore. Four years later, de Stier decided to return to Europe, leaving his Prince George's County residence in charge of his daughter and son-in-law. Charles Benedict Calvert succeeded his father as master of Riversdale. He devoted his life to agriculture through his supervision of this 2000-acre farm and through county, state, and national agricultural societies. His efforts through the United States Agricultural Society were responsible for the creation of the Department of Agriculture in 1853. Henry Clay often visited Calvert at Riversdale, staying in the northeast bedroom. Tradition maintains that he wrote a draft for the Compromise of 1850 while in that room.