I think I'm done now :) I've found him on the 1911 Canada census, along with the 1920, 1930 and 1940 US census, so I've added all of those (I included text, but this may want to be edited for flow). I think I now have all of his siblings as well - his father had 5 children from his first marriage, but the last one died as an infant. Her mother died a week after childbirth. Burpee (Walter's father) later married his first wife's sister, but she died less than a year after they married. With his third wife (Walter's mother), there were three sons. He died when Walter was a child.
Unfortunately, they're still not connected to global tree. I'm not sure of the best way to find the link. Perhaps someone could get him connected?