I'm looking for a William A. Irwin who was probably born about about 1819 (32 in 1851), probably in Ireland [possibly in England]; living 1871 with wife Sarah & children in St George Parish, Henryville, Iberville County, Quebec. He seems to be confused with another William A. Irwin (?perhaps a cousin or uncle) who was a few years older--both masons.
He married 18 Dec 1849 (in Iberville or Clarenceville, Quebec) Sarah Rose Dudley, who was born 15 Sep 1827, probably in Canada; died 14 May 1891, Somerville, MA.
In the 1871 Quebec census, he was living in St George Parish, Henryville Division, Iberville County Quebec--so I don't think he was the William Alexander Irwin, born May 1814, of Edenroory, Dromore Parish, County Down, Ireland. That William is listed in the 1870 census for Cleveland, Ohio with wife Catherine Kramer and three children; and died 30 Oct 1909 in Los Angeles, CA at age 95.