The aim of this paper is to analyse the phase of South American regionalism in the 21st century. By means of bibliographical research into theories of International Relations (realist), Political Economy (structuralist), International Political Economy and Geopolitics (classical), a historical analysis was constructed of Latin America's search for external autonomy and internal capitalist development, around the construction of a geographical consciousness that is formed from colonisation and will unfold in: 1) political initiatives to build an independent territorial unit in the 19th century and 2) a broader regional identity that adds Brazil; 3) in economic integration projects and institutions in the 20th century; 4) and in the third phase of regionalism in the 21st, which rescues political projects beyond the economy, but which fade in the face of an unfavourable external conjuncture. From this, we were able to understand the third phase of South Americanist regionalism and its transition to a new neoliberal regional agenda.