Hi Michael,
Do you have any other information for people to work with? Any names of the family? There was a ton of migration in the 1870's (not specifically immigration) with lots of existing families spreading into northern areas of the province (Algoma district), and also into Western Canada and others starting to cram into the rapidly industrializing cities. Despite all this growth, the economic situation was also driving many people (both new arrivals and settled families) into the United States so many that came to Canada did not stay.