52 Weeks Challenge 42:Queries: Locating a Marriage Record

   
Seeking assistance in locating the marriage record (and hopefully the parents of): 
Pierre Robillard believed to be b. 27 Jan 1830, Quebec (Death cert.) or Aug 1831 (census records); parents not known
&
Philomene Ducharme (fist name also seen as: Philamina, Philanese)
believed to be b. Nov. 1836 Quebec (census records); parents not known

Year of marriage c.1856 (from census records - 1900 census states married for 44yrs)
First known child:  Mary Jean Robillard  b. Feb 1858 in New York.
Death certificates of Pierre had parents listed as 'unknown'.
Last record of Philomene was the 1920 census where she was residing at the home of her granddaughter, Mary  Virginie (St. Jean) Rainville, in New Bedford, Massachusetts.
Thank you.