Between 1808 and 1824, every mainland Spanish and Portuguese colony in the Americas became independent. The break-up was nearly simultaneous across a continent — fifteen new states from the wreckage — and the leadership came largely from creole elites (American-born Europeans) who had grown up reading the same Enlightenment authors as their metropolitan rulers, yet were barred from the top offices reserved for the Iberian-born. The wars were brutal and vast: Simón Bolívar, the most consequential leader, fought for fifteen years from Venezuela to Bolivia, while José de San Martín marched an army over the Andes to liberate Chile and Peru. The post-independence settlements were unstable in ways that would shape Latin America for two centuries.
The proximate cause was Napoleon's invasion of Spain in 1808, which deposed the Bourbon king Ferdinand VII and left colonial elites with no legitimate metropolitan authority to obey — forcing them to govern themselves de facto through local juntas that initially claimed to rule in the captive king's name. The deeper cause was Enlightenment political theory — the same Rousseau and Locke that justified the American and French revolutions — applied by creoles who resented their exclusion from full political rights and feared both Madrid's taxes and a Haitian-style slave revolt. When Ferdinand returned in 1814 and tried to reimpose absolutism, autonomy hardened into outright independence, and a continent-wide war of attrition followed. Bolívar's Gran Colombia — Venezuela, Colombia, Ecuador, and Panama — was an attempt to unify the new republics on the American model, but it dissolved by 1831, the year of his death; the geography was too brutal, the literate population too thin, the regional elites too jealous of one another. The decisive victories — Boyacá (1819), Carabobo (1821), and finally Ayacucho (1824), where Bolívar's lieutenant Sucre broke the last royalist army in Peru — the point at which the northern and southern liberation campaigns had finally converged on the continent's last royalist stronghold — won the field but not the peace. "He who serves a revolution," Bolívar wrote near the end, "ploughs the sea." The vacuum was filled by caudillo politics — strongman rule on horseback, legitimacy resting on the personal loyalty of armed men rather than on institutions — and by the persistence of colonial-era social hierarchy beneath a republican surface, a combination that recurred, in various forms, until well into the twentieth century.
Modern Latin America's political instabilities — the cycles of populism, military coup, neoliberal reform, populist resurgence — are partly downstream of the unfinished nature of the independence revolutions. The states were created before the nations were, and the settlements left land, mineral wealth, and political power concentrated in narrow elites while the indigenous and mestizo majority remained largely outside the republic. Latin America today has some of the world's deepest inequality and most enduring constitutional churn — Bolivia and Venezuela alone have rewritten their constitutions repeatedly within living memory. That distribution problem — political voice as much as wealth — has not yet been solved.