John MANGAN, b. Ireland in 1848, m. Johanna O'BRIEN, b. Ireland, 1855. They were married in January 1874 in Troy. John's parents were John & Bridget MANGAN and Johanna's parents were John A. O'BRIEN & Johanna SHEA. Johanna O'BRIEN had a brother, Dennis A. O'BRIEN, who married Catherine CLANCY in Troy in 1873. I'm looking for other siblings of Johanna O'BRIEN in Troy & possibly her parents. I'm also looking for any siblings of John MANGAN. I'm researching the following surnames for a possible connection to John & Johanna: DOUGHERTY, LUBY, DWYER, MACK, LEAHY, DENNEY, HURLEY, FITZGERALD. Thank you. Marialice P. Mangan