This monograph explores the role that religion played in the process of Americanizing immigrants to the United States. While cities such as New York, Boston, and Philadelphia have been central to immigration research, the city of Baltimore has been vastly underrepresented. As the second largest immigrant port in the U.S., Baltimore is steeped in Catholic tradition, and is an ideal city for a study on the role of the Catholic Church in Americanizing immigrants. Through the use of oral histories, Church records, and secondary texts, Baltimore is revealed as a haven for Catholic immigrants due to the national parishes found throughout the city. These parishes fostered Americanizing agencies founded by the Catholic clergy which utilized the native cultures found within the enclaves to create a gradual transition into mainstream society. This process of Americanization was deliberate and through the development of the national parishes, newcomers to America experienced the phases of immigrant, ethnic, and American. The preponderance of the evidence suggests that such a gradual method of Americanization would be equally effective today for Catholic immigrants in the United States.