- A.B. Stickney, Compiler, Genealogical Materials, 1838/19591
- A.C.L. Gatewood Papers, 1801/19191
- Aaron Ruble Civil War Letters, 1861/18621
- Abner Osburn, Physician, Papers, 1846/19011
- Adolphus DeBussey, Soldier, Civil War Letters, 1861/1998, bulk 1861/187122
- Adolphus P. Howard Papers, 1850/19381
- Adolphus P. Howard Papers, 1854/19041
- Aileen Shafer, Collector, Material regarding African-Americans, 1829/18845
- Alan Clarke Railroad Research Papers, 1861/20122
- Alfred Hughes Stock Certificates and Receipts, 1852/18651
- Alfred T. Pope, Bethany College Student, Autograph Book, 1860/18641
- Allen D. Frankenberry, Soldier, Civil War Diaries and Memoir, 1862/1905, bulk 1862/18651
- Allen Family Papers, 1766/193333
- Alpheus Garrison Civil War Records, 1804/18881
- Alston Gordon Dayton Papers, 1846/19392