- Gabriel Galt Williamson collection, 1825/19391
- Gaius Dickinson Letters, 1791/19301
- Galt Papers (I), 1745/189238
- Galt Papers (III), 1750/199133
- Galt Papers (IV), 1819/18751
- Gamble Papers, Letters and Photographs, 1774/18861
- Gard Family Correspondence, 1828/1874, bulk 1841/18491
- Garland family papers, 1830/19111
- Garrett Family Papers, 1786/19284
- Garth Family papers, 1798/187215
- Gary Weiner, Collector, Papers, 1773/19381
- Gay family papers, 1829/19222
- Geddy-Harris Archive Records, 1773/1959, bulk 1890/19404
- Genealogy Collection, 1880/20015
- Geo. Gregory Smart collection of Washington and Mount Vernon ephemera, 1793/20176