Do you know if Cornelius had any brothers or cousins???
My husbands gr gr grandfather was Maurice Daniel Hartnett, born in Pennsylvania abt 1851. His family is "suppose" to be from County Cork.
Maurice married Mary Fitzgerald (b abt. 1853/4 in Penn). I found in the 1880 census from Albuquerque, New Mexico Maurice and Mary living there (on the way to California)with 4 daughters, Boarding with them was a Mary or Marg GORMAN, age 55 born in Ireland. Also boarding were 2 woman and 1 man who's last names where Fitzgerald. I believe that these the younger Fitzgeralds were probably brother and sisters to Mary Fitzgerald.....but not sure who this Gorman is.

Does this ring a bell???