Born in Ireland, Keane was ordained a priest for the Archdiocese of Baltimore in 1866. After a stint as Bishop of Richmond, he was appointed by the American bishops to be the first rector of their new university in Washington, D.C. Caught up in the Americanism controversy with his sponsor and ally, Abp. James Gibbons, Keane was ousted from Catholic University and given charge of the see of Dubuque. He resigned that archbishopric in 1911.