Organization of American StatesThe Organization of American States is the world’s oldest regional organization, dating back to the First International Conference of American States, held in Washington, D.C., from October 1889 to April 1890. The Organization was established in order to achieve among its member states—as stipulated in Article 1 of the Charter—"an order of peace and justice, to promote their solidarity, to strengthen their collaboration, and to defend their sovereignty, their territorial integrity, and their independence."