Architectural drawings and photographs of architectural drawings with some related correspondence of residential and public buildings, churches, libraries, theaters, monuments, and bridges including: the Henry Hudson Bridge, Triborough Bridge, and the Manhattan Bridge in New York; Edward Henry Harriman's Arden House in Harriman, N.Y.; the Alfred I. Dupont mansion in Roslyn, N.Y.; the David A. Reed house in Washington, D.C.; the reconstruction of the Grand Army Plaza in New York City; the Memorial Amphitheater for Arlington National Cemetery; and various bicentennial buildings for Yale University. Of note are drawings of the grounds, details of buildings, and furniture for the New York Public Library, 1908-1909.

Drawings and maps, with related clippings, showing proposals for traffic routes; railway and ship terminals; boulevards and streets; buildings; public spaces; bridges; and other projects, located mostly in Manhattan, with some in Brooklyn. Also, a rendering by Jacob Wrey Mould of the Church of the Pilgrims, Brooklyn, New York, is included.

Architectural drawings and photographs of Hoppin and Koen designs including alterations to the residence of R.T. Wilson, Jr., 15 East 57th Street, New York, 1905; Albany County Courthouse, Albany, New York, 1913-1915; Mount Morris Theater at Fifth Avenue and 116th Street, New York, 1911-1912; New York City Fire Department building, East 111th Street and Second Avenue, 1911; Manhattan terminal of the Brooklyn Bridge, undated, not constructed; residences of George B. McClellan at Princeton, New Jersey, and Washington, D.C., 1922; Edith Wharton and Edward Wharton's Lenox, Massachusetts, home, the Mount; New York City Police Headquarters, 240 Centre St., New York; and others.