Anglo-French blockade of the Río de la Plata: Battle of Vuelta de Obligado.
The naval Battle of Vuelta de Obligado took place on the waters of the Paran River on 20 November 1845, between the Argentine Confederation, under the leadership of Juan Manuel de Rosas, and a combined Anglo-French fleet. The action was part of the larger Anglo-French blockade of the Ro de la Plata. Although the attacking forces broke through the Argentine naval defenses and overran the land defenses, the battle proved that foreign ships could not safely navigate Argentine internal waters against its government's wishes. The battle also changed the political attitude toward the Confederation in South America, increasing support for Rosas and his government.
The Anglo-French blockade of the Río de la Plata was a five-year-long naval blockade imposed by France and Britain on the Argentine Confederation ruled by Juan Manuel de Rosas. It was imposed in 1845 to support the Colorado Party in the Uruguayan Civil War and closed Buenos Aires to naval commerce. The Anglo-French navy trespassed into Argentina’s internal waters to sell their products, as Rosas maintained a protectionist policy to improve the weak Argentine economy. Eventually both Britain and France gave in, signing treaties in 1849 (Britain) and 1850 (France) acknowledging the Argentine sovereignty over its rivers.