The Organization of American States (OAS or OEA; Spanish: Organización de los Estados Americanos; Portuguese: Organização dos Estados Americanos; French: Organisation des États américains) is an international organization founded on 30 April 1948 to promote cooperation among its member states within the Americas.
Headquartered in Washington, D.C., United States, the OAS is a voluntary "multilateral regional body focused on human rights, electoral oversight, social and economic development, and security in the Western Hemisphere", according to the Council on Foreign Relations. As of November 2023, 32 states in the Americas are OAS members.
Albert Ramdin of Suriname was inaugurated as OAS secretary general in May 2025, replacing Luis Almagro of Uruguay.
The notion of an international union in the American continent was first put forward during the liberation of America by José de San Martín and Simón Bolívar who, at the 1826 Congress of Panama, still being part of Colombia, proposed creating a league of American republics, with a common military, a mutual defense pact, and a supranational parliamentary assembly. The meeting was attended by representatives of Gran Colombia (comprising the present-day countries of Colombia, Ecuador, Panama, and Venezuela), Argentina, Peru, Bolivia, the United Provinces of Central America, and Mexico but the grandly titled "Treaty of Union, League, and Perpetual Confederation" was ultimately ratified only by Gran Colombia. Bolívar's dream soon floundered with civil war in Gran Colombia, the disintegration of Central America, and the emergence of national rather than New World outlooks in the newly independent American republics. Bolívar's dream of inter-American unity was meant to unify Hispanic American nations against external powers.
Founding of the International Union of American Republics
The pursuit of regional solidarity and cooperation again came to the forefront in 1889–1890, at the First International Conference of American States. Gathered together in Washington, D.C., 18 nations resolved to found the International Union of American Republics, served by a permanent secretariat called the Commercial Bureau of the American Republics (renamed the International Commercial Bureau at the Second International Conference in 1901–1902). These two bodies, in existence as of 14 April 1890, represent the point of inception to which the OAS and its General Secretariat trace their origins.
At the fourth International Conference of American States (Buenos Aires, 1910), the name of the organization was changed to the Union of American Republics and the Bureau became the Pan American Union. The Pan American Union Building was constructed in 1910, on Constitution Avenue, Northwest, Washington, D.C.
In the mid-1930s, U.S. President Franklin Delano Roosevelt organized an inter-American conference in Buenos Aires. One of the items at the conference was a "League of Nations of the Americas", an idea proposed by Colombia, Guatemala, and the Dominican Republic. At the subsequent Inter-American Conference for the Maintenance of Peace, 21 nations pledged to remain neutral in the event of a conflict between any two members. At the 1933 OAS convention in Montevideo, member states agreed to not recognize territorial acquisitions obtained by force. At the 1936 convention in Buenos Aires, member states agreed to enter into a process of arbitration in case there was a threat to peace.
The experience of World War II convinced hemispheric governments that unilateral action could not ensure the territorial integrity of the American nations in the event of external aggression. To meet the challenges of global conflict in the postwar world and to contain conflicts within the hemisphere, they adopted a system of collective security, the Inter-American Treaty of Reciprocal Assistance (Rio Treaty) signed in 1947 in Rio de Janeiro.
The ninth International Conference of American States was held in Bogotá between March and May 1948 and led by United States Secretary of State George Marshall, a meeting which led to a pledge by members to fight communism in the Western Hemisphere. This was the event that saw the birth of the OAS as it stands today, with the signature by 21 American countries of the Charter of the Organization of American States on 30 April 1948 (in effect since December 1951). The meeting also adopted the American Declaration of the Rights and Duties of Man, the world's first general human rights instrument.
The transition from the Pan American Union to OAS would have been smooth if it had not been for the assassination of Colombian leader Jorge Eliécer Gaitán. The Director General of the Pan American Union, Alberto Lleras Camargo, became the Organization's first Secretary General.
The OAS conducted an audit of the 2019 Bolivian general election, which opposition supporters argued was fraudulent. The OAS report contended that the results were marred by "clear manipulation" and significant irregularities leading to the 2019 Bolivian political crisis. Bolivian president Evo Morales resigned soon after, having lost the confidence of the country's military in what he described as a coup. Some media outlets debated whether it should be referred to as a coup. On 21 December, the Technical Mission of Electoral Experts sent by the European Union published a 67-page report which made similar observations and conclusions to that of the OAS. They noted that "there were minutes with an unusually high number of null votes, blank votes and a hundred percent participation of voters in a series of polling stations" and highlighted the general failure of the TSE to declare these irregularities. Studies commissioned by the American left-leaning think tank CEPR argued that the OAS report's statistical analysis was inaccurate and unreliable. The author of the OAS's vote return analysis stated that the CEPR's explanation of the results was implausible. The organization has been criticized by Mexico and the CEPR for their perception of interference into the internal affairs of Bolivia. The OAS observed the subsequent 2020 Bolivian general election stating there was no evidence of fraud. The New York Times concluded that there was some fraud, but that it was unclear how much or if it was sufficient to change the result of the election, and suggested the initial analysis by the OAS was flawed and that the OAS consultant refused to share the data or methods of the OAS analysis.
In November 2021, OAS condemned the outcome of the Nicaraguan general election. In April 2022, Nicaragua reported the completion of its withdrawal process from the OAS initiated in November 2021. The OAS stated that, due to the terms of treaty, the withdrawal would not take effect until 2023. The move was completed on 19 November that year.
Significant milestones in the history of the OAS since the signing of the Charter have included the following:
1959: Inter-American Commission on Human Rights created.
1959: Inter-American Development Bank created.
1960: First application of the Inter-American Treaty of Reciprocal Assistance against the regime of Rafael Trujillo in the Dominican Republic.
1961: Charter of Punta del Este signed, launching the Alliance for Progress.