This chapter describes the ideas and activities of the American Political Science Association (APSA) in the field of citizenship education in public schools. The main purpose of the APSA reports, recommendations, and kindred activities pertaining to citizenship education was to bring the high school social studies curriculum into conformity with political scientists' conceptions of citizenship and citizenship education. The chapter explains the myriad strategies employed by political scientists to foster citizenship education in pre-collegiate settings. It illuminates textbook writers the points of convergence and divergence between the pedagogical goals of political science and the aims of citizenship education in high schools. The three conceptions of citizenship and citizenship education emanated from the three leading traditions or paradigms in political science: Traditionalism, Behavioralism, and Post-Behavioralism. As a marked departure from Traditionalism, Behavioralism celebrated empiricism and positivism, urging the use of value-neutral research methods in pursuit of regularity and lawlike generalizations.