opposed Rosas formed a group called or May Brotherhood. It was a literary group that became politically active and aimed at exposing Rosas' actions. Some of the literature against him includes The Slaughter House, Socialist Dogma, Amalia and Facundo. Meetings which had high attendance at first soon had few members attending out of fear of prosecution. Rosas' opponents during his rule were dissidents, such as José María Paz, Salvador M. del Carril, Juan Bautista Alberdi, Esteban Echeverria, Bartolomé Mitre and Domingo Faustino Sarmiento. Rosas political opponents were exiled to other countries, such as Uruguay and Chile. The 17 year long rule of Rosas was influenced by permanent warfare, both from unitarians and by other countries. The Peru–Bolivian Confederation, allied with France, declared the War of the Confederation against Argentina and Chile; France supported it by imposing a naval blockade over Buenos Aires, which was maintained even after the Peru-Bolivian defeat. The French helped Fructuoso Rivera to oust the Uruguayan president Manuel Oribe from power, so that Rivera helped them against Rosas. France gave up the blockade, but Rosas still supported Oribe in the Uruguayan Civil War to reestablish his rule in Uruguay. The conflict against Rivera led to a renewed conflict with France, this time allied with Britain. The Anglo-French blockade of the Río de la Plata was defeated as well. Justo José de Urquiza, governor of Entre Ríos, thought by then that it was the time required by the Federal Pact to establish a Constitution, but Rosas still kept his idea of doing it after all provinces had already organized themselves. With the bulk of the army of the Confederation on his side and allied with Brazil and Uruguayan forces, Urquiza defeated both the army of Oribe laying siege to Montevideo and then Rosas himself in the battle of Caseros. The 1853 Constitution Urquiza united the provinces in the San Nicolás Agreement, seeking consensus for the new constitution. The Constituent Assembly met in Santa Fe and wrote the Argentine Constitution of 1853. The constitution established a representative, republican and federal government. The legislative power was bicameral, and the executive power was held by a president, elected by an electoral college, with a six-year term and with no chance of reelection. The judiciary was accepted as an independent power. The catholicism was appointed the official religion of the country, but allowing freedom of religion. See also Religion in the United