Rise of the American Party


Anti-Catholic sentiment and mistrust of the foreign-born had always been present in American culture. Increasing Irish and German immigration in the 1840s stoked these fears and the various strands of nativism coalesced into a unified political movement in the 1850s. The express purpose of the American Party (or "Know-Nothings") was to prevent the political advance of Catholics and foreign-born Americans. At its apex in 1855, the party held seventy-five seats in Congress and several state governorships.


Catholic Encyclopedia


 T. Anbinder, Nativism and Slavery : The Northern Know Nothings and the Politics of the 1850s

R.A. Billington, The Protestant Crusade 1800-1860: a study of the origins of American nativism