There is a public tree on ancestry which suggests this 1850 US census entry but says they haven't yet proved this is his family:
https://www.ancestry.co.uk/interacti...11875315/facts
And the 1860 entry for that John and Jacob:
https://www.ancestry.co.uk/interacti...11875315/facts
1850 census Harrison Township, Howard County, Indiana
John Prime 64 farmer, born Massachusetts
Rebecca " 48 born South Carolina
Children: Nathaniel 21, William 19, John T 16, Mariah 12, Mary 9, Margaret 7, Jacob 4, all born Indiana.
1860 census Lafayette, Story County, Iowa
John Prime 75, farmer, born Mass
Jacob M 11 born Indiana.
But John's occupation doesn't match with the father's occupation on your Jacob's marriage cert.