| 1840 FERGUSON Index | ||||
| Last | First | Census | Location | Census |
| Name | Name | State | (County; Town) | Year |
| Ferguson | Samuel | IA Terr. | Dubuque; no twp listed | 1840 |
| Ferguson | Joseph | IA Terr. | Henry; no twp listed | 1840 |
| Furgison | C | IA Terr. | Jackson; no twp listed | 1840 |
| Ferguson | James | IA Terr. | Johnson; no twp listed | 1840 |
| Furguson | C W | IA Terr. | Louisa; no twp listed | 1840 |
| Furguson | Anna | IA Terr. | Van Buren; no twp listed | 1840 |
| Ferguson | Moses | IA Terr. | Washington; no twp listed | 1840 |