General Urquiza called a constitutional convention that met in Santa Fe in 1852. Buenos Aires refused to participate, but the convention adopted a constitution for the whole country that went into effect on May 25, 1853. Buenos Aires recoiled from the new confederation, the first elected president of which was Urquiza and the first capital of which was Paraná. The porteño dissidence was a serious financial handicap to the state, since Buenos Aires kept for itself all the revenues from customs duties on imports. In 1859 Urquiza incorporated Buenos Aires by armed force, but he also agreed to a constitutional revision that underscored the federal character of the government.
Before the unification took effect, however, Urquiza was succeeded in the presidency by Santiago Derqui. Another civil war broke out, but this time Buenos Aires defeated Urquiza’s forces. Urquiza and General Bartolomé Mitre, governor of Buenos Aires, then agreed that Mitre would lead the country but that Urquiza would exercise authority over the provinces of Entre Ríos and Corrientes. Derqui resigned, and Mitre was elected president in 1862; Buenos Aires became the seat of government.
The authority of the new president was progressively weakened by opposition within his own province of Buenos Aires. The pressures of this opposition forced Mitre to intervene in the political struggles of Uruguay and then to fight Paraguay in the War of the Triple Alliance. From 1865 to 1870 an alliance of Argentina, Brazil, and Uruguay carried on a devastating campaign against Paraguay, employing modern weapons and tens of thousands of troops.
The war with Paraguay did not disrupt Argentina’s commerce, as other wars had. In the 1860s and ’70s foreign capital and waves of European immigrants poured into the country. Railroads were built; alfalfa, barbed wire, new breeds of cattle and sheep, and finally the refrigeration of meat were introduced.
