During the Civil War that followed he supported the treaty and joined the National Army. He was promoted to the rank of Sergeant and served as a Lewis gunner. On the morning of 28 June 1922 he reported for duty at 6 a.m. for what would turn into a week of street battles known as the Battle of Dublin. That day, during a break in the battle, he made his way to the nearby Pro-Cathedral where he married his fiancé Mary Douglas and then returned to the fight.