Jules Henri de Sibour designed Congressman Alexander Stewart's residence. Built at a cost of $92,000, it was one of the costliest mansions in the area. Sibour's approach to angular sites was to absorb their irregularities in the building plans, achieving a simple geometric structure that maintains a rectilinear edge on the streetscape. The triangular site of the Stewart House dictated three important facades; with the exception of the entry porch on Massachusetts Avenue, they are all articulated by channeled rustication on the ground story with the two astylar upper floors connected by spandrel sculpture and ornamental panels. The exterior utilizes numerous design elements derived from French eighteenth-century architecture. The relatively planar wall treatment with sunken windows framed by double-story, vertical panels, nearly equal proportions of alternating solids and voids, and the subdued use of curvilinear elements and sculpture are associated with the Louis XVI style. Sibour's plan is also French-inspired in its composition of interconnecting rooms that serve similar functions, either public or private. In contrast, the interiors are decorated in the English Jacobean and Georgian styles, odd historical combinations being common in mansions erected during America's Gilded Age. The Stewart mansion is one of three in the area that Sibour designed early in his career while in partnership with Bruce Price (see Embassy of France and Embassy of Colombia). These mansions established his practice of applying correct, although eclectic, historical vocabularies to beautifully proportioned buildings free of the whimsicalities that his chief rival, George Oakley Totten, often employed.