- Albert R. Gallatin papers, 1795/18281
- Alderman family papers, 1779/19613
- Alexander Brown Papers (I), 1815/19102
- Alexander Hamilton, Jr. Letters, 1832/18331
- Alexander McNutt Glasgow Family Papers, 1823/19032
- Alexandria Gazette Ledgers (MS026), 1833/18664
- Alexandria History Collection (MS240), 1767/20086
- Alexandria Library Company Records (MS002), 1794/20073
- Alexandria Scrapbook Collection (MS003), 1830/18931
- Alfred Leyburn Papers, 1823/1899, bulk 1830/18395
- Allen Family Papers, 1766/193316
- Alumni Association Records, 1833/2014, bulk 1950/20051
- Ambler Papers, 1806/18361
- Ancella Bickley, Historian, Research Papers regarding African-Americans, 1775/2018, bulk 1970/20116
- Anderson Family papers, 1755/195826