The Roman Catholic Church took no official stand on the war. Seeing itself as the church of persecuted outsiders in Protestant America, the Church found itself in a "no win" situation: If it chose a side in the conflict, it would be branded as a traitor by the other side; if it remained neutral, it would be attacked as disloyal by both sides. At Notre Dame, both faculty and students were prohibited from discussions favoring either the Union or Confederate side. Father Edward Sorin, founder of Notre Dame in 1843, sympathized with the North but was able to maintain a neutral stance on campus, with the result that many Southerners continued to attend Notre Dame along side northern sympathizers, including the children of William Tecumsah Sherman. Father Sorin did send seven C.S.C. priests to serve as chaplains in Union regiments and more than eighty Sisters of the Holy Cross to nurse the sick and wounded in Union hospitals. Father Corby joined the chaplains’ corps in 1861 and was assigned as chaplain to the 88th New York Volunteer Infantry in the famed Irish Brigade of Thomas Francis Meagher. The Irish Brigade was constituted primarily of Irish Catholic soldiers.
Father Corby volunteered his services as a chaplain in the Union Army at the request of Father Sorin, now the Superior-General of the Congregation of the Holy Cross. Corby resigned his professorship at Notre Dame, and, with a song on his lips, boarded the train from Chicago:
I'll hang my harp on a willow tree.
I'll off to the wars again:
A peaceful home has no charm for me.
The battlefield no pain