This book’s introduction poses the problem of uncontested adjudication in the federal court system of the United States by focusing on the 2013 decision in United States v. Windsor. While in that case, the Supreme Court reached the merits despite the absence of a continuing dispute between the parties, Justice Antonin Scalia objected that doing so violated the adverse-party requirement, which he viewed as a constitutional requirement imposed by the case-or-controversy language of Article III. In arguing that federal courts may not entertain uncontested claims of right, Scalia’s dissent in Windsor nicely poses the question at the heart of this book. But the book reaches a different conclusion, based on the text and history of the Constitution, and the early practice of Article III courts. Having set the stage, the introduction offers an overview of the book’s argument. Part I describes the early practice of the antebellum federal courts, Part II the rise of the case-or-controversy rule in the early twentieth century, and Part III the continuing relevance of uncontested forms of adjudication. Synthesizing these strands, the book concludes that Article III courts can entertain proceedings to hear and determine uncontested applications to assert or register a claim of right under federal law.