Argentina: Independence Movement

By 1810, Spain's grip on its American colonies had weakened considerably after Napoleon's invasion of the Iberian Peninsula deposed King Ferdinand VII. News of Spain's political crisis reached Buenos Aires, capital of the Viceroyalty of the Río de la Plata, and prompted a week of public deliberation among city leaders known as the May Revolution, held from 18 to 25 May 1810. The result was the formation of the Primera Junta, a local governing body that claimed to rule in Ferdinand's name but in practice ended royal authority in the region.

Not all the provinces of the former viceroyalty accepted the Junta's authority, and years of fighting followed between forces loyal to the new government and those loyal to Spain. Military and political leaders including José de San Martín, Manuel Belgrano, and Mariano Moreno emerged as central figures in the struggle, with San Martín later leading campaigns across the Andes into Chile and Peru to extend the fight against royalist forces beyond Argentina's borders.

On 9 July 1816, delegates gathered at the Congress of Tucumán formally declared the independence of the United Provinces of the Río de la Plata from Spain, a date still marked as Argentina's independence day. Full political stability did not follow immediately, as disputes over the new nation's organization and governance continued for decades afterward, but the 1816 declaration is regarded as the founding act of the modern Argentine state.