Looking for Great Grandfather Mcgrath S Ancestors

I don't have much informationn about my great-grand father. All I know is that he lived In Tracadie, New Brunswick, Canada. I know he had a son named Michel, a daughter Suzanne and another daughter Elizabeth (my grand mother). He ad other children but I don't know their names. Elizabeth married twice. First marriage was to Isidore Allain of Neguac, NB. The second marriage was to Eutrope Robichaud (my grand father) also from Neguac.