<P> The Gran Chaco region remained largely unexplored, and uninhabited, by either Europeans or Argentines until the late 19th century, after numerous confrontations between Argentina and Paraguay during the War of the Triple Alliance . San Fernando was re-established as a military outpost, and was renamed Resistencia in 1876 . </P> <P> The Territorio Nacional del Gran Chaco was established in 1872 . This territory, which included the current Formosa Province and lands presently inside Paraguay, was superseded by Territorio Nacional del Chaco upon its administrative division, in 1884 . </P> <P> Between the end of the nineteenth and the first decades of the twentieth centuries, the province received a variety of immigrants, among them Volga Germans and Mennonites from Russia, Germany, and Canada . They, alongside other immigrants, transformed Chaco into a productive farming region known for its dairy and beef production . </P> <P> In 1951 the territory became a province, and its name was changed to Provincia Presidente Perón . The province was renamed again in 1955 when the government of President Juan Perón was overthrown, returning to the historical name of Chaco . Chaco voters, however, continued to support Peronist candidates in subsequent elections, notably Deolindo Bittel whose three terms as governor in the 1960s and 1970s were each cut short by military intervention . Bitell subsequently ran for vice-president in the 1983 Argentine Presidential elections and later served as mayor of the provincial capital, Resistencia . </P>

Who compose the majority of the population of the chaco