The origins of regional integration in the Americas lie in the South of the Western hemisphere. In fact, the unity of Latin America has been a constant in the regional political discourse. The "wars for independence were not yet over before proposals for political unity began to be heard throughout the newly independent territories" (Mace, 1988, p. 404). Simón Bolívar, the Venezuelan liberator, established his belief in a United States of "formerly-Spanish America" in his messages to the Congresses of Angostura (1819) and Panama (1826), the first attempts at continental integration. However, projects of continental unity never took off. Cultural commonalities notwithstanding, the divisive factors prevailed. Natural obstacles such as huge distances and physical barriers impeded communications. Historical legacies further aggravated regional integration. The social obstacles were also substantial: as colonial power, Spain was primarily interested in the extraction of natural resources. The administrative system it developed served this objective and entailed control over the territory from a single center. Its American colonies were thus ill connected. Disputes over territory or disagreements that were of a regulative nature were prone to distrust, rivalry, and competition. Unsurprisingly, thus, the end of the independence wars triggered civil strife that eventually divided Hispanic South America into nine independent countries. The exception was Brazil, Portugal's single South American colony, which managed to keep its unity. Central America went through a process of fragmentation, too. Only Mexico managed to retain most of its territory -only to lose half of it later to the United States.Subsequent attempts at political unification likewise failed and led to the emergence of pan-Americanism, a softer version of continental union for the management of international relations. Unlike Bolívar's original project, pan-Americanism included Brazil and was centered on the United States instead of the Central American land bridge. Inspired in the 1823 Monroe Doctrine, a US policy that opposed European colonialism in the Americas, the pan-American conferences were international summits held every 4 to 10 years, starting in Washington, DC in 1889. Pan-Americanism conceived of the world as divided in two hemispheres, where Europe embodied the old and the Americas, the new.After World War II, in which most Latin American states remained neutral, regionalism in the Western hemisphere split into two tracks, one political, the other economic. The political track incarnated into the Organization of American States (OAS), based in Washington, DC, which brought all of the Americas together under the aegis of the Monroe Doctrine. The economic track took distance from Washington, changed the focus from political cooperation to economic integration, and, eventually, split into two sub-regions: Central America and South America plus Mexico. This development must be attributed to many factors including the functionalist argument that in...