I looked at the 1860 census and Samuel was aged 24 not 26, making his birth year as 1836.
I found a Samuel Lewis, age 25, who enlisted 16 Oct 1861 as private in A Co Ohio 71st Infantry. Died of disease 5 Mar 1862 at Paducah, KY.Buried at Cairo National Cemetery, Cairo, IL. I could not find any info on the cemetery.
You could write to the Ohio Genealogical Society for info on Civil War soldiers from Columbiana County, OH. Go to the OGS site for a contact address. When writing, always include a self-addressed, stamp envelope.