John Blankenship married a Mary McKeehan in Jennings County on 5/2;7/1830

Allen C. Blankenship is presumable the teenage son of John Blankenship. The rest of John's children appear to have gone to Riley County Kansas, not sure if he did too.

John BLANKENSHIP b: 1808 in IN
Mary MCKEEHAN b: 1810 in PA
Father of John Blankenship
Isham I. BLANKENSHIP b: 1777 in Va
Mother: Mary CHAMBERS b: ABT 1778)

Here is this family in the 1850 census:
17 | 169 169 | John Blankenship | 42 M | farmer 2500 | Ia | | B452 |
18 | 169 169 | Mary Blankenship | 40 F | | Penn | | B452 |
19 | 169 169 | James Blankenship | 18 M | farmer | Ia | | B452 |
20 | 169 169 | Elizabeth Blankenship | 17 F | | Ia | | B452 | Not listed as attending school
21 | 169 169 | Mariah Blankenship | 14 F | | Ia | | B452 | Not listed as attending school
22 | 169 169 | William Blankenship | 12 M | | Ia | | B452 | Not listed as attending school
23 | 169 169 | Martha Blankenship | 10 F | | Ia | | B452 | Not listed as attending school
24 | 169 169 | Allen C Blankenship | 7 M | | Ia | | B452 | Not listed as attending school
25 | 169 169 | Mary L Blankenship | 5 F | | Ia | | B452 | Not listed as attending school