- Alexander, Fultz, and Willson Families Collection, 1770/19701
- Alexandria Black Family Reunion Digital Collection, 1937/20051
- Alexandria History Collection (MS240), 1767/200820
- Alexandria Library Company Records (MS002), 1794/20078
- Alexandria, Virginia City Records (MS019), 1750/1983, bulk 1825/18751
- Alfred Leyburn Papers, 1823/1899, bulk 1830/18391
- Alice Rice Jaffe Papers, 1807/1950, bulk 1919/19501
- Allen Family Papers, 1766/19339
- Alpheus Garrison Civil War Records, 1804/18881
- Alvan Fisher Personal Papers (SC-33), 1822/18521
- Ambler Papers, 1806/18362
- Amelia's friendship album, 1823/18331
- Amos Johnson Ledgers, 1808/1861, bulk 1808/18211
- Amos Koontz Papers I, 1809/1965, bulk 1936/19651
- Ancella Bickley, Historian, Research Papers regarding African-Americans, 1775/2018, bulk 1970/201113