Architectural drawings, specifications, manuscripts, printed materials, photographs, ephemera, collected by Hitchcock, and relating to the work of architects Henry Hobson Richardson and Frank Lloyd Wright, including a letter, 1940, from Wright to Hitchcock suggesting the writing of IN THE NATURE OF MATERIALS; the architectural firm Shepley, Rutan, and Coolidge; furniture designer Charles Rennie Macintosh; and miscellaneous and unidentified architects dating from the sixteenth century to the twentieth century, with the bulk dating from the nineteenth century.