- Alexander Brown Papers (II), 1748/190013
- Alexander Hamilton, Jr. Letters, 1832/18331
- Alexander M. Davis Papers, 1850/18924
- Alfred E. Bradley Papers, 1864/1922, bulk 1916/19181
- Alice Nellie Letter, 1880/19001
- Allen-Kean-Laurence family letters, 1837/19602
- Alumni Association Records, 1833/2014, bulk 1950/20057
- Amelia County, Va. Merchant's Account Book, 1852/1903, bulk 1852/18562
- Amos Koontz Papers I, 1809/1965, bulk 1936/19651
- Amos Koontz Papers II, 1865/19704
- Anatole and Vladimir Kalichevsky Papers, 1871/19551
- Ancient Order of United Workmen. Coldwater Legion No. 8 (Michigan) Ledger, 1885/18962
- Andrew J. Weeks Papers, 1861/1902, bulk 1862/18662
- Anne T. Chapman Papers, 1884/19543
- Annie Baker Tucker's Colonial Ancestral Chart and Family Records, 1888/19191