In 1852, Rosas was defeated in the Battle of Caseros by the Ejército Grande, an alliance between the provinces of Entre Ríos and Corrientes, the colored troops of Uruguay and others of Brazil. The alliance was led by federal antirrosista Justo José de Urquiza, governor of Entre Ríos, who assumed the provisional presidency.
This period lasted until the sanction of a Constitution in 1853, which with some changes has ruled the country until today. It adopted a federal regime, but the province of Buenos Aires separated from the Argentine Confederation, which had to establish its capital in the city of Paraná. In 1859, the Confederation defeated Buenos Aires in the battle of Cepeda, forcing it to sign the Pact of San José de Flores, by which Buenos Aires was reincorporated into what has since been renamed the Argentine Republic. Nevertheless, the definitive reunification was achieved under the direction of Buenos Aires after the battle of Pavón (1861), during the presidency of Bartolomé Miter.
In 1865, Argentina became involved again in a civil war in Uruguay, to which Paraguay responded by occupying the city of Corrientes. After signing a Triple Alliance with Brazil and Uruguay, Argentina took part in the War of the Triple Alliance against Paraguay, which lasted five years and required the participation of ten thousand Argentine soldiers.The Paraguay was finally defeated in 1870, being totally devastated and dead a great part of its masculine population, in spite of its enormous economic cost and in human lives, since it was cause of the continuation of the civil wars in Argentina, this country managed to consolidate its limits in the northeast, since the border was set on the Pilcomayo, Paraguay and Paraná rivers.
Avellaneda was the third and last president of the period of the historic Argentine presidencies. He ruled between 1874-1880.
During the presidency of Miter, and especially of Sarmiento and Avellaneda, Argentina was inserted into the world economy as an agro-exporting country, supported by a broad rail network and the advancement of the education system. After two bloody revolutions in 1874 and 1880, in this last year the city of Buenos Aires was federalized, and a lasting balance was established between the provinces and the capital.
Conservative governments and first radical governments
The president Roque Sáenz Peña obtained that in 1912 the law of secret and obligatory vote or called Sáenz Peña Law was sanctioned.
Between 1878 and 1884 the so-called Conquest of the Desert and the Chaco occurred, in order to end the constant clashes between indigenous and criollos in the border, and appropriate the indigenous territories, tripling the Argentine territory. The first conquest, promoted by Julio A. Roca, consisted of a series of military incursions into the Pampa and Patagonian territories dominated by the original peoples, distributing them among the members of the Rural Society, who financed the expeditions. until the end of the century, since its full incorporation into the national economic system only took place when the mere extraction of wood and tannin was replaced by the production of cotton. The Argentine government considered the natives as inferior beings, without the same rights as the Creoles and Europeans.
Between 1880 and 1916, the National Autonomist Party (PAN) monopolized power on the basis of fraudulent elections, prompted by the system of sung votes and for 25 years, the exclusive figure was General Julio Argentino Roca. The so-called Conservative Republic or Oligarchical Republic organized a successful and modern model agroexportador based on the so-called international division of labor imposed by the British Empire, mainly oriented to the production of meat and grains for the British market. In the traditional story the country was seen at that time as “the granary of the world.”
This economic model generated a concentration of wealth in few hands and the social exclusion of the working classes and the populations settled outside the Pampean region. The economy reached high levels of growth that attracted a great immigration current mainly constituted by millions of Italians and Spaniards, and to a lesser extent followed by Eastern Europeans and Western Asians. The Argentine population, which represented 0.13% of the world population in 1869, would represent 0.55% in 1930, a proportion in which, approximately, it would stabilize since then.