States have long been wary of putting international migration on the global agenda. As an issue that defines sovereignty - that is, who enters and remains on a state's territory - international migration has called for protection of national prerogatives and unilateral actions. However, since the end of World War I, governments have sought ways to address various aspects of international migration in a collaborative manner. This book examines how these efforts to increase international cooperation have evolved from the early 20th century to the present. The scope encompasses all of the components of international migration: labor migration, family reunification, refugees, human trafficking and smuggling, and newly emerging forms of displacement (including movements likely to result from global climate change). The final chapter assesses the progress (and lack thereof) in developing an international migration regime and makes recommendations towards strengthening international cooperation in this area.