Hi,
John had a son William who married Sarah Ann Miller born in Greenwich, England. From the original records I have John Hagan married Mary Adams in Armagh, Northern Ireland in 1829. Jack did marry Mary in 29 Dec 1894 in NSW.
Were are you based? Since I will be in Ireland in a couple of weeks trying to verify John's family history. If I have made any errors now is the time to pick them up.
Thanks,
Rob.