I have a Donald Matheson in my direct line, who moved to Cape Breton in 1825. He was my grandmother's (Mary Louise Matheson Fox) great grandfather. However, my family tree shows he was married to Marian MacDonald. And he died in 1850.
Possibly you are referring to a Donald who was his grandson, but even so, that Donald was not alive near the end of the 19th century.
I've got lots of info on both Donalds' ancestors, if you think we can establish a connection.
How do you relate to your Donald? What source gives his wife as MacRae?
Don Worley