Federalism was adopted, as a constitutional principle, in Australia on 1 January 1901 – the date upon which the six self-governing Australian Colonies of New South Wales, Queensland, South Australia, Tasmania, Victoria, and Western Australia federated, formally constituting the Commonwealth of Australia. It remains a federation of those six "original States" under the Constitution of Australia. Australia is the sixth oldest surviving federation in the world after the United States (1789), Mexico (1824), Switzerland (1848), Canada (1867), and Brazil (1891). Relatively few changes have been made in terms of the formal (written) constitution since Australian federation occurred; in practice, however, the way the federal system functions has changed enormously. The most significant respect in which it has changed is in the degree to which the Commonwealth government has assumed a position of dominance. Instigated by Henry Parkes' Tenterfield Oration of 24 October 1889, the Australian Colonies conducted a series of constitutional conventions through the 1890s. These culminated in a draft Constitution that was put to popular vote in the individual colonies, and eventually approved by the electors, after a final round of changes met the higher threshold of support required in New South Wales. It was then passed into law by the Imperial Parliament in Britain as the Commonwealth of Australia Constitution Act 1900, finalising the process of the Federation of Australia. The rather desultory way in which federation proceeded reflected the absence of compelling urgency. The colonies saw some advantage in removing tariff barriers to inter-colonial trade and commerce, having a greater strategic presence, and gaining access to investment capital at lower rates; individually, though, none of these represented a driving force. Taken together with the emergence for the first time of a distinct sense of Australian national identity, however, they were collectively sufficient. This lack of urgency was also reflected in their desire to create a minimally-centralised union.