- "Justus ut palma a 3 Canto e Alto e Basso" manuscript, 1800/18251
- "Madonna and Child" print by Friedrich Karl Rupprecht, after Zanetti, after Parmigianino chiaroscuro woodcut, 18221
- A.C.L. Gatewood Papers, 1801/19191
- A.J. Morrison Collection, 1754/19751
- Aaron Harmon Collection (MS249), 1815/18361
- Abraham Davenport Ledger, 1804/18331
- Abraham Grove Account Book, 1815/18501
- Account Books, 1782/18951
- Adam Empie Papers, 1811/2004, bulk 1811/18501
- Adam Rinica and George Rinica Account Book, 1822/18481
- Adams Papers, 1782/18901
- Administration records collection, 1776/19761
- Albert R. Gallatin papers, 1795/18281
- Alderman family papers, 1779/19611
- Alexander Brown Papers (I), 1815/19101