My grandmother was Erin Catherine Rigney, b. New Orleans 1894, daughter of William Rigney (b. 1866 Dublin)and Catherine Gunning (b. 1868 Castlereigh, Roscommon). William and his brother John (Jack) both came to N.O. before 1893; sons of John Rigney, (b. abt. 1835, Kings County, now Offlay) and Catherine Garrity (b. abt. 1848, Dublin).
I have seen records of Hugh Rigney in N.O. earlier than the arrival of William and Jack.