- A. Philip Randolph, Civil Rights and Labor Leader, Papers1
- A.B. Stickney, Compiler, Genealogical Materials1
- Aaron Chipps, Coal Miner, Papers1
- Ada Haldeman Ford, Suffragist, Papers1
- Adamston Flat Glass Factory, Glass Cutting Tool1
- Adolphus DeBussey, Soldier, Civil War Letters2
- Adolphus P. Howard Papers1
- African American Photographic Portraits1
- Agnes Smith (1906-1994), Author, Correspondence, Manuscripts, and Publications1
- Alan Clarke Railroad Research Papers27
- Albert Blakeslee White (1856-1941) Papers3
- Albert M. Reese (1872-1965) Papers2
- Albert Moore Reese, Zoology Professor, Miscellaneous Items11
- Alexander Foreman, Photographer, Glass Plate Negatives1
- Alfred A. Bolton, Papers regarding History of Management and Other Material33