Protestant and Catholic missionary organizations contributed to the development of American schooling. On the Protestant side, the American Home Missionary Society and the American Sunday School Union provided missionaries who frequently became active in school activities. More importantly, these agencies, typical of the evangelical alliance of this era, provided a common ideology, seen especially in their fear of a Catholic domination of the Mississippi Valley. The Catholic organizations were seen by Protestants as concrete links between American Catholicism and the despotic powers of Europe, and they served, therefore, to mobilize anti-Catholic sentiment, thus encouraging the formation of common schools. This ideology was important as a driving force in the development of common schooling. Three Catholic organizations were equally important. The Leopoldine Association of Vienna, the Ludwig Missionsverein of Bavaria, and the Society for the Propagation of the Faith of Lyons and Paris raised money for education. They too magnified a threat--the Protestant threat--in order to gain more funds. (RM)