Active in the War of Independence McCurtin participated in many ambushes including the one at Modreeny, 3 June 1921. Shortly after the Truce he went north of the border to assist against the B-Specials. He was arrested and sentenced to ten years' imprisonment at Enniskillen assizes on 13 March 1922 for possession of firearms and ammunition, and transferred to Aberdeen prison in 1923. His brother Austin was a commandant in the National Army, killed during the Civil War in County Laois.