According to the book "Thomas Brush Brown Autobiography", Donald Mcdonell married Sarah Cameron at the home of his step-father, Mr. O'brien, in early 1823. From that point forward I can trace the Mcdonell/Mcdonald/MacDonald family in Ontario to my father's immigration to the US in July, 1923.
Researchers of East Nissouri have noted that Donald Mcdonell and Daniel Mcdonald could be one and the same although I have found no hard evidence of this. Indications are he was born in 1799.
I believe James O'Brien (OBryan) was the step-father. At the time he was married to Catherine Smith (b. abt 1784 in Cornwall. Her father was John Smith the Elder who was a Sgt with the R.R.N.Y)
The only hint I have to actually link Daniel Mcdonald to James O'Brien is that both James and Daniel submitted land petitions on the same day in 1820 at the same place (Waterloo). Each petition was for a 100 acres and they each paid fee's. Catherine had previous the same year petitioned for 200 acres as daughter of a UEL in Waterloo.
Daniel's petition does note his father, James Mcdonald, immigrated from Scotland to Canada abt 1777.
Any information or suggestions as how to continue this search will be appreciated as this is my brickwall.