I know that our moderator wants to close this thread and I do not want to get off topic, but to clarify the experience of Roman Catholic immigrant groups in the U.S., I would like to refer to a paper I published over 40 years ago on the role of the Roman Catholic Church in the Americanization of the Polish immigrant.
The most important step taken by the American Catholic hierarchy to aid the immigrant and the action which showed that the Church was not anxious to Americanize the immigrant too swiftly was the establishment and legalization of national parishes. According to the Code of Canon Law promulgated in 1918, "No parish may be established for the faithful of diverse languages or nationalities living in the same city or territory without a special Apostolic induit, nor parishes consisting of families or persons without such an induit; if such have already been established, no change may be made without consulting the Apostolic See."
http://www.sjsu.edu/people/jennifer...onzell%20Polish%20RCC%20Assimilation.pdfThese "national parishes" avoided the appointment of bishops for each nationality group and prevented phyletism in the American Roman Catholic Church.