- A.B. Stickney, Compiler, Genealogical Materials1
- A.C.L. Gatewood Papers1
- Abner Osburn, Physician, Papers1
- Adolphus DeBussey, Soldier, Civil War Letters2
- Adolphus P. Howard Papers2
- African American Photographic Portraits1
- Aileen Shafer, Collector, Material regarding African-Americans2
- Alan Clarke Railroad Research Papers28
- Albert Blakeslee White (1856-1941) Papers1
- Albert M. Reese (1872-1965) Papers1
- Allen D. Frankenberry, Soldier, Civil War Diaries and Memoir1
- Allen Family Papers30
- Alpheus Garrison Civil War Records1
- Alston Gordon Dayton Papers6
- American Flint Glass Workers Union Papers1