The Potato famine drew millions of Catholic Irsh Immigrants to the U.S. - swelling the Catholic population.
Michael Corcoran
Thomas Francis Meagher
Father Mathew's Disciples: American Catholic Support for Temperance, 1840-1920.
Growth of the Roman Catholic Church in the United States (1933 Thesis, ebook available through Google Scholar)
John Hughes and a Catholic Response to Slavery in Antebellum America
Abolitionists, Irish Immigrants, and the Dilemmas of Romantic Nationalism
Immigrants in the City: New York's Irish and German Catholics
Special Catholic Activities in War Service (WWI)
Catholic Southerners, Catholic Soldiers