- Institute for the History of Technology and Industrial Archaeology Records, 1875/2005, bulk 1980/20055
- International Association for Identification Records, 1842/2012, bulk 1910/19591
- Ira E. Robinson Papers, 1818/19301
- Irvine-Saunders Family Papers
1745-1910 Inclusive9
- Isaac Ambler Papers, 1828/18601
- Isaac Bird correspondence, 1824/18341
- Isaac Caruthers, Monroe County Merchant, Store and Tavern Ledgers, 1819/18631
- Isaac Horne Ledgers, 1824/18704
- Isabella Furnace Account Book (Page County, Va.), 1827/18542