Mercosur was created by the Treaty of Asunción in 1991.
Argentina, Brazil, Paraguay and Uruguay signed the treaty on 26 March 1991, establishing a process aimed at creating a common market in the Southern Cone of South America. The name Mercosur comes from Mercado Común del Sur, meaning Southern Common Market in Spanish.
The treaty set out objectives including the free movement of goods, services and factors of production, a common external tariff and a coordinated trade policy toward non-members. The Ouro Preto Protocol of 1994 gave Mercosur an international legal personality and formalized important institutional arrangements.
Venezuela joined as a full member in 2012 but has been suspended since 2016. Bolivia became a new full member in 2024 after completing the accession process. Mercosur is distinct from the Andean Community and the Pacific Alliance, which are separate Latin American integration groupings with different memberships and institutional histories.