- "Scenes from Behind the Wall: Images of East Germany, 1989/90" exhibit collection, 1989/20121
- A. E. Dick Howard papers, 1928/20173
- A. Jane Duncombe Architectural Papers, 1952/20021
- A. Patrick L. Prest, Jr. papers, 1941/20141
- Abraham Anson papers, 1939/20056
- Academic Affairs: Academic Program Reviews, 1976/2018, bulk 1992/20182
- Admiral Thomas J. Lopez Papers, 1973/20143
- Advisory Committee Research Collection, 1772/20174
- Agnes Wolf papers, 1966/20061
- Alan Clarke Railroad Research Papers, 1861/20121
- Albert J. Wasserman Papers, 1925/20031
- Alexandria History Collection (MS240), 1767/20081
- Alexandria Library Board Records (MS416), 1937/20202
- Alexandria Library Company Records (MS002), 1794/20075
- Alexandria Library Records (MS098), 1937/20131