After an initial loss to Labor at the 1946 election, Menzies led the Liberals to victory at the 1949 election, and the party stayed in office for a record 23 years—still the longest unbroken run in government at the federal level. Australia experienced prolonged economic growth during the post-war boom period of the Menzies Government (1949–1966) and Menzies fulfilled his promises at the 1949 election to end rationing of butter, tea and petrol and provided a five-shilling endowment for first-born children, as well as for others. While himself an unashamed anglophile, Menzies' government concluded a number of major defence and trade treaties that set Australia on its post-war trajectory out of Britain's orbit; opened Australia to multi-ethnic immigration; and instigated important legal reforms regarding Aboriginal Australians.

How many years did the Liberals stay in office after the 1949 election?