John J. Kelleher

Hi, I'm looking up a John J. Kelleher, a cousin of mine. From what I know, he served with general Patton's third army and was from New York. He was inducted into service april 30, 1943 and was killed in action on Feburary 5 1945. I am trying to find out more about him, what units he served with, how he died, his serive records,etc.
any help appreciated
thanks
John Paul Wallace