- Alan Clarke Railroad Research Papers, 1861/201228
- Alan R. Shirkey photograph collection, 1877/19171
- Albert Blakeslee White (1856-1941) Papers, 1888/19291
- Albert C. Swindler Papers, 1862/1929, bulk 1862/18642
- Albert Frederick Wilson papers, 1840/19343
- Albert M. Reese (1872-1965) Papers, 1873/19541
- Albert R. Gallatin papers, 1795/18281
- Albert Taylor Bledsoe and Sophia Bledsoe Herrick letters, 1858/19081
- Alderman family papers, 1779/19616
- Aldine S. Kieffer letter, 18811
- Alexander Brown Papers (I), 1815/191012
- Alexander Brown Papers (II), 1748/190013
- Alexander Family Papers
1800-18907
- Alexander Farish Robertson Papers, 1867/19313
- Alexander Haight family collection, 1764/197614