- Inge Horton Architectural Collection, 1964/199923
- Institute for the History of Technology and Industrial Archaeology Records, 1875/2005, bulk 1980/200516
- International Association for Identification Records, 1842/2012, bulk 1910/19597
- Ira E. Robinson Papers, 1818/19301
- Ira E. Robinson Papers, 1869/19511
- Irvine-Saunders Family Papers
1745-1910 Inclusive15
- Isaac & Josiah Williams Brick Company, Account Books, 1844/19901
- Isaac B. Smith, Farmer and Music Teacher, Newspaper Clippings and Other Material, 1840/19841
- Isaac McNeel (b.1830) Papers, 1850/19081
- Isaac White Letters, 1861/19381
- Isabella Bain memory album, 1870/19131
- Isabella Furnace Account Book (Page County, Va.), 1827/18541
- Israel C. White Papers, 1867/19411
- Ives Family Papers, 1850/19106