A republic in southern South America. Independent from Spain in 1816, Argentina was torn by regional separatism through much of the 19th century. This is reflected in the issuing of separate stamps by several Argentine provinces during 1858-80. Large-scale European immigration and investment after the 1880s made Argentina the most economically advanced nation in South America. Since 1930, Argentina has, more often than not, been ruled by authoritarian military regimes. During World War II, the government was sympathetic to the Axis, and after the war, a large number of ex-Nazis found sanctuary in Argentina. In 1946, Juan Domingo Peron was elected president, and he dominated the country's political life until his death in 1974, although he was in exile 1955-73. Chronic, unresolved economic and social tensions erupted into virtual civil war during 1976-80. Both leftist guerrillas and the military government used terror and violence to further their ends, and thousands died in the conflict. During this period, the Argentine economy deteriorated badly. High unemployment and spiraling inflation provoked intense popular dissatisfaction with the ruling junta. Argentina's invasion of the Falkland Islands in early April 1982 was, at least in part, an attempt to unify the nation. Since 1983, Argentina has been ruled by a succession of civilian regimes. Since 1991, the government has been working to deregulate and stimulate the economy, with mixed results.