- Abner Osburn, Physician, Papers, 1846/19011
- Abolitionist Movement Collection, 1834/18881
- Absalom See Account Books, 1854/18693
- Account Book Including Recipes and Home Remedies, 1856/18691
- Account Books, 1782/18953
- Account book (N.H.), 1856/18741
- Accounts, 19th Century, 1836/18971
- Ackerly Family Papers4
- Adam Empie Papers, 1811/2004, bulk 1811/18502
- Adams Papers, 1782/18902
- Addie Rogers Bound Sheet Music Collection, 1827/18603
- Adele Goodman Clark papers, 1849/19784
- Administration records collection, 1776/19767
- Admiral John Randolph Tucker Papers, 1865/18972
- Adolphus P. Howard Papers, 1850/19381