Meeting in the northern city of Tucumán, representatives of the United Provinces of the Río de la Plata signed a declaration severing ties with the Spanish crown. The move capped six years of armed struggle and set the stage for José de San Martín's campaigns to liberate Chile and Peru. July 9 became Argentina's national independence day, celebrated ever since with military parades in Buenos Aires.
By 1816 the revolutionary junta in Buenos Aires had been fighting royalist forces for six years without formally declaring independence, wary of provoking Spain or unsettling monarchist sympathizers among the elite. Pressure from radical factions, and the need to legitimize the war effort internationally, finally pushed delegates from the provinces to gather in Tucumán, a city chosen partly for its distance from both royalist Peru and the fractious coastal capital.
On July 9, thirty-some delegates signed the declaration, written in Spanish and, in a symbolic nod to the indigenous population, translated into Quechua and Aymara for public reading. The document's original text has since been lost; only later transcriptions survive.
The declaration gave San Martín the legal cover to launch his audacious crossing of the Andes the following year, carrying the revolution into Chile and eventually Peru. Tucumán's colonial house where the signing occurred, the Casa Histórica, was later restored and remains Argentina's most visited historic site outside Buenos Aires.