This book examines leading Supreme Court decisions involving the powers of the Court, the president, and Congress, as well as cases addressing American federalism and Americans' economic rights. By analyzing both the Court's opinions and voting patterns from 1791 through 2018, this volume presents an overview of the role of the Supreme Court in the legal and political system of the United States throughout its entire history, regularly relying on Robert McCloskey's theory of the nation's three major constitutional eras and the Supreme Court Database in its organizational approach. Over 100 of the Supreme Court's most significant rulings, old and new, are covered and clarified in this volume to provide an objective, reliable, and valuable resource for students, academics, legal professionals, and the general public alike.