- Allen-Kean-Laurence family letters, 1837/19602
- Alpheus Garrison Civil War Records, 1804/18881
- Alumni Association Records, 1833/2014, bulk 1950/20053
- Alvan Fisher Personal Papers (SC-33), 1822/18521
- Amos Johnson Ledgers, 1808/1861, bulk 1808/18211
- Amos Koontz Papers I, 1809/1965, bulk 1936/19651
- Ancella Bickley, Historian, Research Papers regarding African-Americans, 1775/2018, bulk 1970/201113
- Anderson Family papers, 1755/195828
- Andrew Delmar Hopkins Papers, 1787/19431
- Andrew S. Core, Typescripts and Charts, 1804/18881
- Andrew Steele Fulton Account Books, 1825/18341
- Anita Cutright Burnett, Collector, Papers, 1790/19351
- Ann Gilman album, 1835/18391
- Ann Smith Academy Papers, 1807/19101
- Anna Burton Ellett Collection, 1751/19322