- T. Catesby Jones papers, 1875/19252
- Talbott-Tolbert Family Papers, 1784/19311
- Tangi Meli scrapbook, 1912/19161
- Tate Thompson Brady Family papers, 1785/20056
- Tax reports of public service corporations from the State Corporation Commission,, 1895/20151
- Taylor Family Papers, 1903/195711
- Taylor collection of Lewis family papers, 1700/19502
- Taylor family papers, 1894/19831
- Tazewell Family Papers, 1838/1978, bulk 1860/18701
- Telluric Company, Investment Company Record Book, 1891/19541
- Terrill-Porterfield Families, Papers regarding the Civil War and Other Material, 1716/1994, bulk 1840/19201
- Terry Burton, Collector, Ogden House Collection, 1886/19971
- Thaddeus Podratsky, Collector, Records Regarding the Socialist Party, 1911/2006, bulk 1911/19371
- The 'Standard Guide" Ready Reference Map of Washington, [D.C.], 19151
- The Cox-McPherson Ledgers and Papers
1758-1949 Inclusive6