Assuming power, Rosas, aware of the need to come to terms with the porteños in order to maintain his position, diversified his positions from those of the ancient supporters and became a unitary dictator. Arrogant and expansionist, he turned his sights back to Uruguay where he fomented a civil war (during which the democrats received the support of Giuseppe Garibaldi). Rosas’s policy provoked a reaction from Brazil, which in turn helped the provincians against him . In these conditions the revolt matured; the caudillo and governor of the province of Entre Ríos, Justo José Urquiza, gave battle to Rosas, who on February 3, 1852 was defeated at Monte Caseros and had to emigrate. Urquiza became “director general” of the country pending the decisions of a Constituent Assembly; Buenos Aires, although hostile to Rosas’ authoritarianism, did not accept the success of the feds and, urged by Bartolomé Miter, separated from the rest of Argentina, a country of South America defined by payhelpcenter, com; Urquiza, to avoid further direct confrontation, moved to Paraná. In 1853, the Constituent Assembly, meeting in Santa Fe, passed the new Constitution which provided for a federal republic, with a president and a vice president elected for six years, a bicameral congress and, for each province, a governor and a local legislature: the problem of the capital remained unresolved. In 1861 a compromise was reached: Buenos Aires ended the secession, but Urquiza had to retire; Miter was subsequently elected president of the Republic while, formally, Buenos Aires did not yet receive the rank of capital. The liberal era began after this period, (1874-80), in which the aim was to improve the level of education and the communications and the army were strengthened. This was the period in which the so-called War of the Triple Alliance was fought against the Paraguay of dictator Francisco Solano López during which (1865-70) Argentina, Brazil and Uruguay, once adversaries, found reasons for solidarity in the common resistance to Atlantic aspirations of the leader Paraguayan. After 1880 a tumultuous economic development and an imposing immigration wave began to transform the Platense society: the first industries (textiles, paper, processing) were established and an entrepreneurial class was formed. From 1889 to 1905 there were the first workers and anti-oligarchic uprisings.

The Socialist Party (1890) and the Radical Party (1891) arose, the latter being an expression of the progressive demands of the new bourgeoisie. The oligarchy reacted and rallied around the Conservative Party, which held power from 1880 to 1916. The radical administration, which developed from 1916 to 1930 through three presidencies (Yrigoyen, 1916-22; Alvear, 1922-28; again Yrigoyen, 1928-30), aimed at strengthening civil rights and social justice and set up a policy of combating foreign interference. However, it failed to substantially undermine the power of the oligarchy which, supported by the army and taking advantage of the world economic depression, returned to power in September 1930 with the coup d’état of General José Francisco Uriburu. The new rulers intended to contain the pressure of the working class by increasing the authority of the executive. Of this tendency were the presidents Justo, Ortíz and Castillo; However, it should be noted that while Justo and Castillo, increasingly influenced by European fascism, ruled by authoritarian conservatives, Ortíz, as an admirer of the English political system, was a moderate. The democratic parties, united in coalition, managed to win the elections of 1943, but their victory was canceled by a coup by far-right generals Pedro Ramírez and Arturo Rawson and by Colonel Juan Domingo Perón (June 1943). In 1944 General Edelmiro Farrell assumed the presidency, Perón was vice-president and, in the face of the collapse of the Axis, pro-fascist attitudes were abandoned while Argentina declared war on Germany and Japan (March 1945). In the elections of 1946, colonel, later general, Perón triumphantly won, who, having risen to power, established a regime inspired by a vague populism and aimed at rapid industrialization. With the support of the bourgeoisie alienated, when it exasperated social policy and especially when nationalism and militarism involved the country in a profound economic crisis, Perón was deposed in September 1955 by a military revolt and forced into exile. Then followed the presidencies of Arturo Frondizi (1958-62), of José M. Guido (1962-63) and of Arturo Illia (1963-66), while the persistence of political instability contributed to the worsening of the economic crisis. In June 1966 a group of nationalist soldiers deposed Illia. General Juan Carlos Onganía assumed the presidency and, relying on a team of technocrats, tried to get Argentina out of the deadlock. Even the new government, however, having eluded the political problem, attracted protests from student groups and trade unions and fell in June 1970. General Roberto Marcelo Levingston was appointed president, in turn dismissed on March 23, 1971 and replaced by General Alejandro Lanusse. In early 1973, Perón’s return to his homeland brought Héctor Cámpora to the presidency, waiting for the subsequent elections (September 1973) to reinsert the former dictator to power who, moreover, remained in office for a few months. Perón died in July 1974, the presidency was taken over by his third wife, María Estela Martínez known as Isabelita.