This collection primarily contains architectural drawings, photographs, business records and reference materials related to the projects and designs of architectural and engineering firm Abbott, Merkt and Company. A subsidiary portion of the collection includes drawings, photographs and papers related to the life and career of Richard H. Tatlow, III, president of Abbott Merkt, as well as the firms and agencies for which he also worked.

Correspondence, memoranda, and legal and financial documents of Keppel. The files deal largely with Keppel's personal and professional life during his tenure as President of the Carnegie Corporation, and also include some files from his years as Newton D. Baker's Third Assistant Secretary of War, and as Dean of Columbia College. There are extensive files of correspondence from and to Keppel's parents and children, as well as files concerning his activities in organizations such as the Century and Columbia University Clubs. The letters from friends and business associates concern American education, politics, business, and cultural life, particularly in the New York metropolitan area, from 1900 to 1943.