| Location | Sub-location | Title | Author/Comp./Editor |
| I Families | IMLAY | Ancestors and Some Descendants of Wm. Henry Imlay of Hartford, Conn. 1780-1858. | |
| CS71.I47 | INGERSOLL | Genealogy of the Ingersoll Familiy in America 1629-1925 / comprising descendants of Richard Ingersoll of Salem, MA John Ingersoll of Westfield MA and John Ingersoll of Huntington, Long Island | Avery, Lillian Drake |
| I Families | INGERSOLL | Ingersolls of Hampshire | Lt. Charles S. Ripley |
| I Families | INGHAM | Certain Topics on the Ingham, Waterhouse and Allied Family | |
| I Families | INNES | James Innes and His Brothers of the F. H. C. | Carson, Jane |
| I Families | INNES | Two Innes Families of Philadelphia, PA | Waterman, Helen, comp. |
| I Families | ISAAC | Ancestry of Mary Isaac ca 1549 - 1613 Wife of Thomas Appleton | Davis, Walter Goodwin |
| I Families | IRELAND | Some Account of the Ireland Family, originally of Long Island 1644 - 1880 | Joseph Norton Ireland |
| I Families | IRVINE | Some Irvine Descendants of Edward Erwin of Long Glade | |
| I Families | IRWIN | Genealogy of the Irwin Family in New York founded in the Hudson River Valley | William Irwin (1700-1787) |
| I Families | IRWIN | Irwin Bible Rec. | |
| I Families | ISON | Descendants of Gideon Ison | Carlie Breeding |
| I Families | ISON | Descendants of Gideon Ison, I | Carlie Breeding |
| I Families | IVERS | Ivers Family Scrapbook | Mike and Danna Clancy, comp. |
| I Families | IVERSON | Jeppe Iverson Family Book |