This handbook captures the revival of the study of the American political past that has taken shape over the past few decades. Because this renewal has been the result of an interdisciplinary effort, this volume features the work of historians, political scientists, sociologists, and scholars in such fields as law and communications. Its contributors cover traditional chronological periods along with topics in public policy. Some of traditional topics, such as transportation, tax, and economic policy, have been revitalized through interdisciplinary work. Others, such as the histories of conservatism and religion in politics, reflect political history’s fruitful connections with intellectual, social, and cultural history. Throughout the essays reflect political history’s classic focus on government, institutions, and public life, often now informed by work on gender, region, ideas, race, and culture. Two themes, political participation and statebuilding, recur through these essays. Neither had a straightforward history. The right to vote was not a story of ever-expanding access. If we broaden the category to include all manner of public and even seemingly private actions, the range of political actors and events widens and diversifies considerably. While the rediscovery of “the state” owes much to political sociology and American Political Development, the impact on historical scholarship has been wide and deep. Most essays on policy areas show some of the influence of the careful study of institutions and the tangled process of policy development. Even more, work on the early nineteenth century has reminded historians of an active state: nineteenth-century state and local governments regulated all manner of things, from slave codes to voting rights to alcohol consumption and sale to medical practices, some of which would become federalized and a matter of rights in the late twentieth century. The study of “the state” added new layers of complexity and opened new debates in the histories of sexuality, labor, women, and race. Like political participation, the study of the state promises to spark new debate.