Independence was to be the fortune of the Spanish Americans, and a continuance of despotism, for a while, the lot of the Spaniards.
As the region of the viceroyalty of La Plata had been the first to cast off the authority of the home government, so it was the first to complete its separation from Spain.

Despite the fact that disorder was rampant everywhere and that most of the local districts could not or would not send deputies, a congress that assembled at Tucuman voted on July 9, 1816, to declare the "United Provinces in South America" independent.

Comprehensive though the expression was, it applied only to the central part of the former viceroyalty, and even there it was little more than an aspiration.

Mistrust of the authorities at Buenos Aires, insistence upon provincial autonomy, failure to agree upon a particular kind of republican government, and a lingering inclination to monarchy made progress toward national unity impossible.

In 1819, to be sure, a constitution was adopted, providing for a centralized government, but in the country at large it encountered too much resistance from those who favored a federal government to become effective.
In the Banda Oriental, over most of which Artigas and his horsemen held sway, chaotic conditions invited aggression from the direction of Brazil.