The Australian colonies had a period of extensive multi-ethnic immigration during the Australian gold rushes of the latter half of the 19th century, but following Federation in 1901, the Parliament instigated the White Australia Policy that gave preference to British migrants and ensured that Australia remained a predominantly Anglo-Celtic society until well into the 20th century. The post-World War II immigration program saw the policy dismantled by successive governments, permitting large numbers of Southern European, and later Asian and Middle Eastern migrants to arrive. The Menzies Government (1949-1966) and Holt Government dismantled the legal barriers to multi-ethnic immigration and by the 1970s, the Whitlam and Fraser Governments were promoting multiculturalism.