What year did Australia become a federation?

The story behind the answer

1901 is correct because on 1 January 1901 the six British colonies—New South Wales, Victoria, Queensland, South Australia, Western Australia, and Tasmania—united to form the Commonwealth of Australia. This followed the Commonwealth of Australia Constitution Act 1900 (UK), which came into force on that date. Edmund Barton was sworn in as the first Prime Minister in Sydney, marking the birth of the nation.

Context tip: 1899 saw key referendums that paved the way, but federation legally began in 1901—think “New century, new nation.” The later dates mark other milestones (1910: national currency and a majority Labor government; 1911: creation of the Federal Capital Territory). Remembering 1-1-1901 (New Year’s Day) is an easy cue for Australia’s federation.