Hi, I first found Stephen B. Gardner in 1850 living in Iowa City, JOhnson County, IA. He was living with his family, father John, 46, b. NC, farmer; mother Margaret, 42, b. IA; Aaron, 19, IA, William P. 16, IA, Pohn or John, 14, IA; Stephen B., b. IA, 8 and Benjamin F., b. IA, 6.
Then I found a Stephen B. Gardner in 1860 living with his family in Eugene, Lane Co., OR. John, head household, 55, NC, farmer; wife Margaret, b. IN, 50; William, b. IN, 25, carpenter; Stephen B., b. IA, 20, farmer and Benjamin F., b. IA, 18, farmer.
I'd say these two families are the same because of the match of data points, e. g., names and place of birth.
However, the 1870 Curry Co., OR Census S. B. Gardiner only matches on one point and that being place of birth Iowa and date of birth is about the same time frame. I can't tell you if John and Margaret are the parents of this S. B. Gardiner.
Then in 1880 Pleasant Hill, Curry Co., OR Stephen B. and family appear. The first names of the family, approximate date of births, and states of birth match the 1870 Census, Stephen's father's state of birth on the 1880 match the 1860 Census. It's conceivable that John and Margaret are Stephen's parents but not proven.
I'd want a copy of or information on Stephen's birth in IA which will list his parents before tying this family as parents and son (Stephen).I'd post on the Iowa, Johnson County Message Board on where to get birth info or do a Google search for 1842 Johnson County Iowa birth records. Successful Hunting!