- A. Jane Duncombe Architectural Papers, 1952/20021
- A. Patrick L. Prest, Jr. papers, 1941/20143
- A. Rufus Tonelson Papers, 1922/19753
- A. Willis Robertson Papers, 1921/1988, bulk 1946/196614
- A.E.S. Stephens Papers, 1949/19614
- Abraham Anson papers, 1939/20056
- Adele Blow Chatfield-Taylor family papers, 1899/19772
- Adele Goodman Clark papers, 1849/19785
- Administrative Management Society records, 1941/1987, bulk 1941/19871
- Adolphus DeBussey, Soldier, Civil War Letters, 1861/1998, bulk 1861/18711
- Alan Clarke Railroad Research Papers, 1861/20122
- Albert I. Godden Papers, 1949/19722
- Albert J. Wasserman Papers, 1925/20031
- Albert L. Sturm Papers, 1904/19885
- Alberta Pfeiffer Architectural Collection, 1929/19762