- Inge Horton Architectural Collection, 1964/199913
- Institute for the History of Technology and Industrial Archaeology Records, 1875/2005, bulk 1980/200512
- International Association for Identification Records, 1842/2012, bulk 1910/19595
- Ira E. Robinson Papers, 1818/19301
- Irvine-Saunders Family Papers
1745-1910 Inclusive11
- Isaac & Josiah Williams Brick Company, Account Books, 1844/19901
- Isaac B. Smith, Farmer and Music Teacher, Newspaper Clippings and Other Material, 1840/19841
- Isaac Horne Ledgers, 1824/18702
- Isaac L. Carey Correspondence, 1850s-1867, 1850/18672
- Isaac McNeel (b.1830) Papers, 1850/19081
- Isaac R. Trimble letters, 1862/18701
- Isaac White Letters, 1861/19381
- Isabella A. Myler album, 1860/18691
- Isabella Furnace Account Book (Page County, Va.), 1827/18541
- Ives Family Papers, 1850/19109