In the late 1960s identity politics emerged on the political landscape and challenged prevailing ideas about social justice. These politics brought forth a new attention to social identity, an attention that continues to divide people today. While previous studies have focused on the political movements of this period, they have neglected the conceptual prehistory of this political turn. Linda Nicholson’s engaging book situates this critical moment in its historical framework, analyzing the concepts and traditions of racial and gender identity that can be traced back to late eighteenth-century Europe and America. She examines how changing ideas about social identity over the last several centuries both helped and hindered successive social movements, and explores the consequences of this historical legacy for the women’s and black movements of the 1960s. This insightful study will be of particular interest to students and scholars of political history, identity politics and US history.