*On this date in 1816, Argentina gained independence from Spain. This resulted from the Argentine War of Independence, fought from 1810 to 1818.
The population of Buenos Aires was highly militarized during the British invasions of the Río de la Plata, part of the Anglo-Spanish War. Buenos Aires was captured in 1806 and then liberated by Santiago de Liniers with forces from Montevideo. A new British attack in 1807 captured Montevideo but was defeated in Buenos Aires and forced to leave the viceroyalty.
In the political structure, most authoritative positions were filled by people designated by the Spanish monarchy, primarily from European Spain. Argentine patriotic forces, led by Manuel Belgrano, Juan José Castelli, and José de San Martín, fought against royalist forces loyal to the Spanish crown. Fearing a counterattack, all the population of Buenos Aires capable of bearing arms were arranged in military bodies, including African slaves. The Argentine victory and emancipation from Spanish colonial rule led to the partial abolition of slavery.
The territory of modern Argentina was part of the Spanish Viceroyalty of the Río de la Plata, with its capital city in Buenos Aires, the seat of government of the Spanish viceroy. Modern Uruguay, Paraguay, and Bolivia were also part of the viceroyalty and began their push for autonomy during the conflict, becoming independent states afterward. The vast territory and slow communications led most populated areas to become isolated from one another.
The wealthiest regions of the viceroyalty were in Upper Peru (modern-day Bolivia). Salta and Córdoba had closer ties with Upper Peru than with Buenos Aires. Similarly, Mendoza in the west had closer relations with the Captaincy General of Chile, despite the Andes mountain range serving as a natural barrier. Buenos Aires and Montevideo had a local rivalry in the La Plata Basin. They had access to naval communications, enabling them to stay more in touch with European ideas and economic advances than the inland populations. Paraguay was isolated from the rest of the world. On July 9, 1816, an assembly convened in San Miguel de Tucumán and declared complete independence, accompanied by provisions for a national constitution.
