Acclaimed biographer John Loughery tells the story of John Hughes, son of Ireland, friend of William Seward and James Buchanan, founder of St. John's College (now Fordham University), builder of Saint Patrick's Cathedral on Fifth Avenue, pioneer of parochial-school education, and American diplomat. As archbishop of the Archdiocese of New York in the 1840 and 1850s and the most famous Roman Catholic in America, Hughes defended Catholic institutions...