I did receive your email that contained of your family members buried at the cemetery, and I did send a reply.My Hotmail account later sent me a message saying that there was a delay and that they would resend my message later.Since I didn't receive a "message sent failed" message from Hotmail, I just assumed that you finally received my email.
I'll email a copy of the 1900 Census to you after I post this message.In the meantime, I would like to just say that I do think it is entirely possible for your William to have been born in Canada, and still be related to those you had mentioned.Another possible scenario for the differences in the censuses is that often times enumerators asked the questions wrong.For instances the enumerator may have asked "Where are you from?" instead of "Where were you born?".The two questions do not necessarily have the same answer, especially if a family recently moved.The question "Where are you from?" may have been asked in the Washington censuses that you cited, and the proper response would have been "New York", even if nobody was born there.
After reading your post though, I feel that this may not even be the biggest problem.In every census that I found William Graham, it said that his parents were born in Scotland.If this is true, then Walter Graham could not be William's father.
I still think you need William Graham's obituary and/or his death certificate.Since your Donald Graham's grandson, I believe (I'm not positive) that you legally can obtain William Graham's death certificate.
Anyhow, I'll email the census to you.I'll try the file size small, since the size of the documents are quite large.