th, and permitted increased trade between colonists and Mapuches.
The drive for independence from Spain was precipitated by usurpation of the Spanish throne by Napoleon's brother Joseph. A national junta in the name of Ferdinand—heir to the deposed king—was formed on September 18, 1810. The junta proclaimed Chile an autonomous republic within the Spanish monarchy. A movement for total independence soon won a wide following. Spanish attempts to reimpose arbitrary rule during what was called the Reconquista led to a prolonged struggle.
Intermittent warfare continued until 1817, when an army led by Bernardo O'Higgins, Chile's most renowned patriot, and José de San Martín, hero of Argentine independence, crossed the Andes into Chile and defeated the royalists. On February 12, 1818, Chile was proclaimed an independent republic under O'Higgins' leadership. The political revolt brought little social change, however, and 19th century Chilean society preserved the essence of the stratified colonial social structure, which was greatly influenced by family politics and the Roman Catholic Church. The system of presidential absolutism eventually predominated, but wealthy landowners continued to control Chile.
Toward the end of the 19th century, the government in Santiago consolidated its position in the south by ruthlessly suppressing the Mapuche Indians, finally completing the conquest begun more than three centuries earlier. In 1881, the government signed a treaty with Argentina confirming Chilean sovereignty over the Strait of Magellan. As a result of the War of the Pacific with Peru and Bolivia (1879-83), Chile expanded its territory northward by almost one-third and acquired valuable nitrate deposits, the exploitation of which led to an era of national affluence. Chile established a parliamentary style democracy in the late 19th century, but degenerated into a system protecting the interests of the ruling oligarchy. By the 1920s, the emerging middle and working classes were powerful enough to elect a reformist president, whose program was frustrated by a conservative congress. In the 1920s, Marxist groups with strong popular support arose.
In 1970, Senator Salvador Allende Gossens, a Marxist physician and member of Chile's Socialist Party, who headed the "Popular Unity" (UP or "Unidad Popular") coalition of the Socialist, Communist, Radical, and Social-Democratic Parties, along with dissident Christian Democrats, the Popular Unitary Action Movement (MAPU), and the Independent Popular Action, won a plurality of votes in a three-way contest. The Chilean Congress conducted a runoff vote between the leading candidates, Allende and former president Jorge Alessandri and chose Allende by a vote of 153 to 35.
Allende's program included advancement of workers' interests; a thoroughgoing implementation of agrarian reform; the reorganization of the national economy into socialized, mixed, and private sectors; a foreign policy of "international solidarity" and national independence; and a new institutional order (the "people's state" or "poder popular"), including the institution of a unicameral congress. The Popular Unity platform also called for nationalization of foreign (U.S.) ownership of Chile's major copper mines.
An economic depression that began in 1967 peaked in 1970, exacerbated by capital flight, plummeting private investment, and withdrawal of bank deposits by those opposed to Allende's socialist program. Production fell and unemployment rose. Allende adopted measures including price freezes, wage increases, and tax reforms, which had the effect of increasing consumer spending and redistributing income downward. Joint public-private public works projects helped reduce unemployment. Much of the banking sector was nationalized. Many enterprises within the copper, coal, iron, nitrate, and steel industries were expropriated, nationalized, or subjected to state intervention. Industrial output increased sharply and unemployment fell during the Allende administration's first year.
Other reforms undertaken during the early Allende peri