Today Puerto Ricans are the largest single ethnic group in the city boroughs of the Archdiocese of New York. Oxcart Catholicism on Fifth Avenue presents a fascinating exploration and analysis of the Catholic church's efforts in New York City to meet the needs of migrant Puerto Ricans. Ana Maria Diaz-Stevens combines socio-historical methods and the insights of her personal participation in this process to create the first book-length assessment of this important event in twentieth-century American Catholic history. Diaz-Stevens begins by tracing the historical development of Catholicism in Puerto Rico, first under Spain and then after 1898 under the United States. She suggests the ways in which Puerto Ricans differed from the Irish, Italian, Polish, or other Catholic groups that came to New York. At the same time, she breaks new ground by describing significant differences between Puerto Ricans and Mexican-Americans in the practice of religion. After examining how institutional Catholicism in New York had grown from a loose mix of early nineteenth-century village parishes into a centralized cosmopolitan institution by the middle of the twentieth century, Diaz-Stevens presents a brief review of three historical periods of Puerto Rican migration to the city. She details the development of the "basement church" among Puerto Ricans as a specialized means of maintaining continuity with island traditions within a big city environment. She also discusses key church leaders, such as Francis Cardinal Spellman, Ivan Illich, Robert Fox and Robert Stem, describing how their attempts to deal with a people who presented "problems" evolved into an innovative ministry to Puerto Ricans. In the process, the Spanish-speaking Apostolate moved beyond existing models of ethnic assimilation into a post-Vatican activism, oriented towards social and community needs.