This chapter aims to survey historical and sociological factors in order to set the stage for a discussion of controlling principles of social justice. It is concerned with the historical and legal aspects of American experience with normative difference. In the American context, early efforts to accommodate religious difference were shaped by the clearly liberal conviction that an official political stance of liberality should be adopted by the federal government. The chapter describes different tension between an appreciation of the importance of toleration in dealing with the problem of pluralism, on one hand, and the refusal to practice toleration when normative difference seems intolerable to dominant sentiments, on the other. Social pluralism of some sort has been a prominent feature of American life from arrivals of Puritans in New England onward. The normalizing function of law may be invoked when immigrant communities bring with them cultural practices that stray too far from beliefs and practices of the dominant culture.