Looking for information on John Johnston and Mary (Murphy) Johnston.I understand they were from in Cavan County, but don't have dates.John may be buried in Ireland. Mary was buried in Ontario, Canada in 1869.They had three daughters that I know of:Rosanna b. 1829 Ireland(d. in Detroit 1909), Margaret (d. in Detroit?) and Maria (d. in Canada?).Any help or info is appreciated.