Diane Igo’s database on Ancestry.com lists John C. Ramey as a son of Thomas Ramey & his first wife Mary “Polly” Jones, but I am skeptical of that attribution, since the 1860 census shows Thomas with a son John age 17, who would have been born about 1843. It doesn’t seem very likely that Thomas would have two sons who survived to adulthood and both used the name John, even if they were born to different mothers. (When there are two children with the same given name, usually either one died very young, before the second was born, or else the first names are ceremonial or memorial only, and at least one of them goes by their middle name.) It does appear, though, from the 1850 census that all of Thomas’s children by his first wife were raised by someone else after Mary died, rather than living with he and his second wife Malinda Murphy. So I suppose it is possible. (If true it would make John and Nancy first cousins.)

Morgan Co. marriage book 1, p. 119 records license issued to John C. Ramey and Nancy Jones on 11 Mar 1852 , no return.

(There is some possibility that John’s wife could instead be Nancy Jones b. 1834, daughter of Capt. Joe Jones & Emily Boyd. But this Nancy is much more likely, because the other children of James W. Jones and Lucinda Brown lived nearby, and because John and Nancy named two of their first four children James and Lucinda.)

1860 census of Rowan Co., Kentucky, Morehead precinct, enumerated 4 Aug, lists on p. 38 as family #288/293:
Ramey, J. C., 27; Nancy, 24; Marion A. (male), 6; James K., 4; Lucinda, 2; Mary J., 1. All born in Kentucky.