The Ninth Edition of this pathbreaking casebook continues its tradition of comprehensive coverage, with problems and exercises that allow students to hone skills as counselors, litigators, and policy advisors. These virtues have become especially important in light of the many changes to immigration and citizenship law since the Eighth Edition went to press in mid-2016. This new edition opens with a reworked foundational chapter that guides students through the casebook in two key dimensions: a basic framework for constitutional immigration law, and an overview of the core administrative law principles that recently have risen to prominence in the making of immigration and citizenship law. This Ninth Edition has thoroughly updated coverage of admissions categories, unauthorized migrants, admission procedures, detention, citizenship, removability, refugees and asylum, federal enforcement, and state and local measures. The treatment of every topic is streamlined, making for a slimmer volume. In each chapter, the Ninth Edition emphasizes both core and cutting-edge issues, while optimizing teachability for a wide variety of course settings.