Recently I returned to research my mother's side of the family and learned my grandfather served with the Expeditionary Forces. Here starts my brick wall. He was born in the US but his parents were born in Canada (not sure if that would make any difference). He was born and raised in Massena, NY and traveled between NY and Kingston, Canada.. He served witht he 41st Regiment, 156th Battalion. He was injured at the Battle of Vimy, and when he returned to Canada he was in and out of the hospital from 1917 to 1921 when he died from the affects of the gases the German's used. I was searching the newspaper archives and found an article in the Canton Commericial Advertiser that he lost his American citizenship on the grounds of being an "undesirable alien" when he enlisted in the Canadian Forces. I thought perhaps it was because he had to pledge his allegience to Canada therefore losing his American citizenship. But I am not sure that is the case from talking with others.I have his enlistment papers and have requested any other information they may have available in hopes I would find more information. I am looking for advice on the best avenue to take to find more info.