Argentina declared independence from Spain on July 9, 1816.
Six years after the formation of the first Argentine government on May 25, 1810, the Congress of Tucumán declared independence for the United Provinces of South America which included present day Argentina and Uruguay.
The May Revolution of 1810 in Buenos Aires was the beginning of the Argentine War of Independence, and the beginning of the end of Spanish rule in South America. It wasn’t the first revolt, but it was the first revolt that didn’t fail.
The restoration of King Ferdinand VII to the Spanish throne in 1815 forced the Americans to decide whether they would continue on their own or submit again to Spanish rule.
After fighting Royalists all over South America, the Argentines chose their own destiny.