John B. Bannon excelled in four distinct capacities: as a pastor of a thriving Catholic congregation in St. Louis; as a chaplain with the First Missouri Confederate Infantry at Pea Ridge, Corinth, and Vicksburg; as a diplomat winning Irish support for the cause of the Confederacy; and as Ireland's greatest preacher in the 1880s.William Barnaby Faherty's latest book, Exile in Erin: A Confederate Chaplain's Story, looks at new historical research...