Transcripts of the "Jus" letters, 1868-1869; of correspondence between O'Callaghan and Richard Gilmour, Bishop of Cleveland, 1884; and of the letter in which O'Callaghan acknowledges that he wrote the "Jus" letters, 1896; copies of his citizenship papers, record of death, will, obituaries, and a photograph of his portrait; and parish history material from St. Colman's Parish, where he served as pastor.