The Organization of American States (OAS) is the oldest multilateral regional organization in the world. It was founded in 1948 by the United States and 20 Latin American nations to serve as a forum for addressing issues of mutual concern. Over time, the organization expanded to include all 35 independent countries of the Western Hemisphere (though Cuba currently is excluded from participation). The organization’s areas of focus have also shifted over time, evolving in accordance with the priorities of its member states. Today, the OAS concentrates on four broad objectives: democracy promotion, human rights protection, economic and social development, and regional security cooperation. It carries out a wide variety of activities to advance these goals, often providing policy guidance and technical assistance to member states. This book provides an overview of the OAS history and issues for Congress, with a focus on illicit drug trafficking and terrorism issues.