Born in Brooklyn, New York, John McDonnell received his education at Cathedral College and Saint John’s Seminary in Brooklyn. He was ordained a Catholic priest on May 30, 1931, and served as an assistant at Saint Peter Claver’s Church, Brooklyn; Holy Innocents Church, Brooklyn; Saint Gerard’s Church, Hollis; Saints Peter and Paul’s Church, Brooklyn; and Saint Mary Star of the Sea, Brooklyn. He entered military service and was commissioned a U.S. Army chaplain in April 1940, and deployed to the Philippine Islands where he was serving at the time of the Japanese attacks on Pearl Harbor and the Philippine Islands. Following the fighting on Bataan, he was captured and held as a Prisoner of War by the Japanese, and reported missing in action. He was declared killed in action on January 22, 1945.



