My ggggrandfather John Mangan was a drover in co.Cavan, lived in Billy Hill, Cootehill area. He married Margaret Connell and they had 5 sons,Terrance, John, William, James and Owen Peter. John died in 1840 or so. I am looking for his parents names and any siblings. Margaret claimed to have descended from the great Dan O'Connell but I have no record of how. I am also looking for her family info.