I do not know for certain who your S.L. Vermillion might be, but I do have a possibility for you to investigate. Stephen L. Vermillion (b. Apr. 28, 1859 in Licking County, OH) is the right age range of the person you have found in the 1880 Iowa census.Stephen was the son of Wilson E. Vermillion (b. Sep. 4, 1821 in Loudon County, VA) and Christina Smith Vermillion (b. 1827 place unknown). Stephen was the seventh of twelve children.I have no marriage or family information on Stephen that would help you.I realize the 1880 Iowa census states S.L. was born in Iowa, but I have learned that many people of that era were born in places other than where the census records show.If I find additional information, I will contact you.