This essay examines Theda Skocpol's landmark 1992 book, Protecting Soldiers and Mothers, and discusses its influence historians of the U.S. welfare state. The first section summarizes the book's “state-centered” approach and its central arguments and discusses its reception. It pays particular attention to critiques from women's and gender historians, who challenged Skocpol's characterization of Progressive Era “maternalist reform” particularly for its failure to account for racial politics or the limitations of rooting women's claims to social citizenship in mothering. The second section explores Skocpol's influence on historians of the U.S. welfare state in the past twenty-five years. Scholars of women and gender followed Skocpol's call to “bring the state back in,” bringing the insights of two decades of social and cultural history to the arena of state-building. In the process, they illuminated the centrality of race and racial politics to American social policy and citizenship in ways that Skocpol largely elided. Skocpol's discovery of the peculiar forms of American social provision also profoundly influenced welfare state scholars, who uncovered the vast reach of the “hidden” or “submerged state” in shaping unequal citizenship and political identities around race, gender, sexuality, and other axes of difference. Finally, the essay discusses historians’ attention to an aspect largely absent from Protecting Soldiers and Mothers—the voices, perspectives, and actions of participants in welfare state programs and policies—which has deepened and expanded understanding of the processes and effects of welfare state-building in the past twenty-five years.