museum in Winterthur, Del., U.S., near Wilmington, that specializes in American decorative arts and furnishings. Occupying a mansion built in 1839 by James Antoine Bidermann and his wife, the great-aunt of Henry Francis du Pont, the museum limits its collections to American domestic architecture, furniture, metalware, textiles, paintings, prints, and other objects made in the period from 1640 to 1840. The museum displays much of its collection in some 175 period rooms, each complete to the last detail. The mansion was inherited in 1927 by Henry Francis du Pont, who built up the collection and opened the renovated and expanded building as a museum in 1951.