Would any of the Americans posting here know where I'd find out about an Irish soldier in the US army during the Great War?

Cecil Gifford, my grandmother's brother, was in National Homes for Disabled Volunteer Soldiers, Bath, New York in 1930. He apparently joined up in 1917 in the medical department as a corporal, and left for the reason "W.D. Ai" or W.D. Cei maybe, #27 (?), then re-enlisted as a private in 1921 in Co K, 29th Infantry, and left because of "reduction of army".

He is listed as suffering from CPI - constant public intoxication, I think - and so was presumably one of those victims of the war who were shattered by their experiences.

I've been told that Cecil died in 1932, in the worst of the Depression, from a fall in the mountains, days after trying to cross into Canada; at the border he apparently listed his occupation as "laborer" and his means as "destitute", and was refused entry. (This was the son of a prosperous Dublin solicitor.) I haven't seen this record myself.

Would any of the ex-military lads here know where I could ask about his army record, and also where I could find out what happened to Co K 29th Infantry, and what happened to whatever part of "the medical department" he was in?

I've had a look around the web, and it seems that Company K were the first American soldiers to set foot in the French battlefields, and were gassed and otherwise under severe pressure during 1918.