To aid in understanding how the process of ethnic succession has worked in America, both a conceptual overview and an indepth analysis of a particular situation that occurred over the past four decades in the Philadelphia school system are presented. Resulting from this historical investigation are a series of highly useful guidelines. The first chapter examines the subtle and not so subtle ways in which ethnicity affects the lives of Americans, and addresses specific topics such as ethnic succession and the new pluralism, diversity, ethnicity and occupational choices, patterns of ethnic succession in America, the growth of ethnic power blocs, political changes, and other issues. The next chapter focuses on a case of ethnic succession: the entry and upward movement of blacks in teaching and administrative posts in the Philadelphia schools in the 60's and early 70's and their partial replacement of Jews and Italians with the assistance of white Protestant cosmopolitan leaders of the school system. This case study should be viewed against the backdrop of the social trends that are described throughout the document. Although it is not examined indepth, it is recognized that the ethnic composition of both the teaching staff and student body is of great significance in the educational process. (Author/AM)