Thanks Roger for your suggestions. I have been doing the things you suggested. Part of the problem is his common name of Joseph Kelly and the fact that members from his family tended to use a date of birth that was a little off from what is found in the Irish Civil records. Even my grandmother was confused as to her exact date of birth and to compound the problem, her civil birth record and parish birth record do not match exactly. I do know that Joseph was in Ireland for their 1901 census. I have been tracing his brothers and will be getting a probate record of one of them. Also, when one brother died in Boston in 1924, the obituary said a brother came from Washington D.C. I suspect that was him. Also, the 1920 census said that he was naturalized.
Do any army records exist for those that were wounded or were those records lost?