After learning when Dennis Hogan was married (1858 in St. Louis), just yesterday, I looked again at the 1860 census in question. I'm sure it is him as the occupation, wife's name and child's name all fit. His father's name was Edward D. Hogan and his mother, Catherine Gahan. I don't find them in St. Louis at all, so I suspect that they remained in Wexford County.