- Abigail Brown Shaw Cole diary, 1859/18692
- Abner Osburn, Physician, Papers, 1846/19011
- Abolitionist Movement Collection, 1834/18881
- Abraham Lincoln Collection, 1860/19651
- Absalom See Account Books, 1854/18692
- Account Book Including Recipes and Home Remedies, 1856/18691
- Account Books, 1782/18955
- Account book (N.H.), 1856/18742
- Accounts, 19th Century, 1836/18971
- Ackerly Family Papers5
- Adalbert J. Volck Collection of Etchings, 1861/19792
- Adam Empie Papers, 1811/2004, bulk 1811/18503
- Adams Papers, 1782/18902
- Adelaide Colcock Papers, 1863/18702
- Adele Goodman Clark papers, 1849/19784