South America's political systems reflect layered historical forces:
Pre-Columbian civilizations (Inca, Muisca, Mapuche, Guaraní, etc.) contributed governance concepts, communal land systems, and symbolic heritage. Many countries recognize indigenous languages/rights constitutionally (Bolivia, Ecuador, Colombia, Peru).
Inspired by US/French/Haitian revolutions. Led by creole elites (Bolívar, San Martín, O'Higgins). Established republics with presidential systems—often unstable, caudillo-dominated.
Military regimes (Brazil 1964–85, Argentina 1976–83, Chile 1973–90, Uruguay 1973–85, Paraguay 1954–89) justified by anti-communism, "national security." Left deep scars: disappeared persons, institutional erosion, economic neoliberalism.
Institutional strength, inequality, corruption, resource nationalism, and social movements continue shaping governance across the continent.