I have not found French in the 1870 census. In 1860 he was listed as age 7 months, with his mother and her parents, and in 1880 with his parents as a son, age 20, but there is no son near 10 by any name in the 1870 census, nor any grandson with the George W. Stamper family.

Some online family trees identify him with the French Epperhart who married Jenny Fraley in 1901, but that seems very unlikely, since that French Epperhart was twenty years older, according to census records.