The history of Argentina can be broken into several periods: the colonial period under Spanish rule until independence in 1816; the period of nation-building and civil wars between federalists and centralists in the 19th century; major immigration in the late 19th century that grew the population and economy; the rise of Juan Peron in the 1940s-50s who expanded workers' rights; the military dictatorships between the 1960s-1980s known as the Dirty War when thousands were disappeared; the return to democracy in 1983; and more recent administrations including the Kirchners in the 2000s who reduced poverty through industry and import controls.