The aim of this article is to analyze a specific case of 'ethnic succession'. This topic emerged in the social sciences in the early 1900s, within the first Chicago school (the Robert Park school). Since that time, many models of succession (drawing upon biological ecology) have been presented. In this paper, a succession in one specific field and one specific place is analyzed: an unfinished process of takeover of a Roman Catholic parish by the rapidly growing Hispanic population from the shrinking Polish American population in the West Side of South Bend in northern Indiana. This process meant also the cultural elimination of the Hungarian Americans from the 'independent' religious life in the town's quarter. In the multicultural contexts, religion is often closely related to ethnicity, and in the well-known theory authored by Milton Gordon, religion is one of three possible bases of ethnicity in American society. In the case discussed here, the two ethnic groups, Hispanics and Polish Americans, belong to the same religious denomination. Moreover, historically speaking, Roman Catholicism has been a very significant element of their ethnic identities. From the recent cultural point of view, however, these are two quite different types of Catholicism. Ethnic succession discussed in this text has important consequences for the cultural features of Catholicism in the whole town. In the article, the local Polish American community and the Hispanic community is briefly presented, and then the 'succession' problems discussed. To the extent it makes sense (and the empirical material is available), the elements of the 'process of passage' and the 'ceremony of passage', important for socio-cultural anthropology, are presented as well.