Brown's victory divided the enemy's forces, and secured the United Provinces' control of access to the interior waterways, and made possible their advance on Montevideo.

On 25 May 1810 the May Revolution in Buenos Aires deposed viceroy Baltasar Hidalgo de Cisneros and established a local government known as the Primera Junta.

Montevideo, at the eastern side of the Río de La Plata (the Banda Oriental, modern-day Uruguay), did not acknowledge their authority, and recognized instead the Cortes of Cádiz established in Spain.

The Montevidean squadron under Jacinto de Romarate destroyed the first flotilla from Buenos Aires, which went up the Paraná River carrying reinforcements to the Paraguay campaign, at the Battle of San Nicolás.

On 5 November 1813, after the resignation of José Julián Pérez, Juan Larrea joined the Second Triumvirate in Buenos Aires, along with Gervasio Antonio de Posadas and Nicolás Rodríguez Peña.

General Manuel Belgrano was retreating to La Quiaca in the north, after the defeats at Vilcapugio and Ayohuma, Patria Vieja in Chile was being invaded by the forces of the Lima and due to internal conflicts was approaching the Disaster of Rancagua.

Larrea chose to promote an agreement with Guillermo Pío White, a wealthy American merchant native of Boston who was sympathetic to the revolutionary cause, who would front the funds necessary to finance the acquisition of vessels and equipment, with a promise of later compensation, tied to the success of the enterprise.

On 7 July 1813 a group of thirteen revolutionary soldiers under the command of lieutenant José Caparrós made a surprise and successful incursion in Martín García Island, at the time in royalists hands, and defended by 70 men.

On the revolutionary side, after receiving his commission as commander, lieutenant colonel Brown started his campaign by sailing his small new fleet to Colonia del Sacramento (in today's Uruguay).

Romarate formed his ships in an east–west line, covering the channel from the anchorage in a semicircle, supported from land by a battery of two cannons and gunfire from the island's troops under midshipman José Benito de Azcuénaga.

Brown questioned the way in which the rest of the squadron "conducted themselves during the action, even though having sent all the signals and having gone personally on my boat before midnight the night before and requested their support, all of which was in vain".

Having secured the front, Romarate sent the sloops Americana and Murciana, to the gunboat Perla and the Salvador's launch to confront the revolutionary division deployed on the north channel, which after a light exchange of fire retreated and joined the rest of the squadron.

Rebel Commanders Benjamin Seaver and Elias Smith, and also the chief of the embarked troops, the French captain Martín de Jaume, second lieutenant Robert Stacy, midshipman Edward Price, sailors Richard Brook and William Russell, and cook Peter Brown were among the casualties.

At 5:00 pm on that day Romarate sent a note to the commander of the Montevideo garrison Miguel de la Sierra, informing he had few casualties, four dead and seven wounded,[contradictory] he had disembarked on the island and judged that, given the losses suffered, as soon as the patriot fleet was in condition it would retreat to Buenos Aires.

He asked his commander for more powder and ammunition in all calibers, and urgent reinforcements to annihilate the retreating ships before they could seek refuge in port.

If Your Excellency has expulsed from that port as I believe, Mercurio, Paloma, Hyena and Cisne, and they are near the islands of Hornos or Valizas, they are lost to the forces of Buenos Aires, and if not, their absence would be very painful in this critical situation.

If he could attack by surprise and with sufficient speed before Romarate could disembark his troops and change the balance of forces, it was feasible to conquer the garrison.

The Spaniards were overwhelmed and surrendered after about 20 minutes of combat, where lieutenant Jones of the Zhepyr captured the land battery, turned the cannons against the royalist ships and raised the United Provinces flag on the island.

The last skirmish was held on the dawn of the 15th when the sloop Carmen under Commander Spiro, who had approached to spy in the night, directed a few volleys of musket fire towards the enemy.

From officers and sailors: Captain Elias Smith, Third Lieutenant Robert Stacy, helmsman Antonio Castro, cabin boy Eduardo Price, first class sailors Ricardo Brook and Guillermo Russell, second class Francisco Guevara, Salomón Lyon, Felipe Rico, Lázaro Molina and Joaquín Uraqui, and cook Pedro Brown.

[10] Not having received the supplies and reinforcements he requested, and knowing of the help promised by Fernando Otorgués, second of José Gervasio Artigas, who before the imminence of the end of the siege of Montevideo, which they had abandoned at the beginning of the year and confronted Carlos María de Alvear, Romarate took advantage of the winds which have veered from the southeast incrementing the rising tide, to escape by the sand banks, and was forced to hide by the end of the Uruguay River.

The Battle of Martín García was then the beginning of a campaign of 100 days which led by Brown ended Spain's naval power in the Río de la Plata and forced the surrender of their last bastion in Montevideo.