Australia fought alongside Britain in World War I, notably with the Australia and New Zealand Army Corps (ANZAC) in the Dardanelles campaign (1915). Participation in World War II brought Australia closer to the United States. Parliamentary power in the second half of the 20th century shifted between three political parties: the Australian Labour Party, the Liberal Party, and the National Party. Australia relaxed its discriminatory immigration laws in the 1960s and 1970s, which favored Northern Europeans. Thereafter, about 40% of its immigrants came from Asia, diversifying a population that was predominantly of English and Irish heritage. An Aboriginal movement grew in the 1960s that gained full citizenship and improved education for the country's poorest socioeconomic group.