Simón Bolívar dreamed of a union of American republics in 1826
At the Congress of Panama in 1826, Bolívar proposed a league of newly free American republics with a shared army and a supranational parliament. Only Gran Colombia ratified the treaty, and civil wars soon buried the plan. More than a century later, a far looser version emerged as the Organization of American States.
The Panama gathering drew envoys from Gran Colombia, which then spanned modern Colombia, Ecuador, Panama and Venezuela, together with Mexico, Peru, Argentina, Bolivia and Central America. Their grandly named Treaty of Union, League and Perpetual Confederation aimed to unite Hispanic America against outside powers. It failed as Gran Colombia fractured, Central America broke apart and the new states turned toward purely national concerns.
Regional cooperation returned at the First International Conference of American States, held in Washington in 1889 and 1890. Eighteen nations set up the International Union of American Republics with a permanent office called the Commercial Bureau, and the OAS dates its origins to 14 April 1890, when both existed. A conference in Buenos Aires in 1910 renamed the office the Pan American Union, and its headquarters building went up that year on Constitution Avenue in Washington.
The interwar years added rules. At Montevideo in 1933 members agreed not to recognise territory seized by force; at Buenos Aires in 1936, a conference convened by Franklin Roosevelt, they committed to arbitration when peace was threatened, and 21 nations pledged neutrality if any two members fought. Colombia, Guatemala and the Dominican Republic even floated a League of Nations for the Americas. The Second World War persuaded governments that no country could defend itself alone, leading to the Rio Treaty of 1947, a pact of collective security.
The OAS itself was founded on 30 April 1948. Based in Washington, it describes itself as a voluntary body working on human rights, election monitoring, development and security in the hemisphere. It counted 32 member states as of November 2023, and Albert Ramdin of Suriname took over as secretary general from Uruguay's Luis Almagro in May 2025.
Source: Organization of American States
