Through a combination of theoretical and historical analysis, the author develops the thesis that the concepts of "race" and "ethnicity" are socially constructed. With case studies of the incorporation of Blacks and Irish immigrants into the social structure of the United States, Richard Williams demonstrates that the social values that have been placed on these groups result from their placement into specific labor categories rather than from attributes inherent to the groups. The author first analyzes the process by which the social identities of Blacks and Irish developed in their native...