He took part in the ST Mihiel and Muese Argonne Offensives and received recognition for these by the gold bars and stars on his WW1 Medal.
Thankfully John returned to the USA uninjured when the war ended. A few years after he got American citizenship, he decided to return to Ireland (1923). In 1925, he married Alicia Brennan from Upper Grange.
Today, there are 12 of John Brennan’s great grandchildren are attending Gowran N.S. including a teacher Kathryn Kennedy. He also has a great great grandchild in Junior Infants, Michael O’Keeffe.