In concert with policy trends, theory and research on the ways in which school context affects student outcomes have focused almost exclusively on academic achievement in recent years. Given the fundamental role that schools should play in civic education, and the potential for schools to affect civic equality, more empirical and theoretical research is warranted to help predict and explain how schools affect civic outcomes. The author outlines the ways in which schools act as civic institutions and analyzes how theories of school effects might be applied to hypotheses regarding youth civic behavior and attitudes. The author provides two examples of mechanisms that provide unique pathways to civic learning in schools--student diversity and the existence of a micro-political environment--and discusses the consequences of the unequal distribution of civic opportunities in schools. She concludes with a discussion of the challenges for empirical research on the civic effects of schools.