A British settlement was established in Van Diemen's Land, now known as Tasmania, in 1803, and it became a separate colony in 1825.[40] The United Kingdom formally claimed the western part of Western Australia (the Swan River Colony) in 1828.[41] Separate colonies were carved from parts of New South Wales: South Australia in 1836, Victoria in 1851, and Queensland in 1859.[42] The Northern Territory was founded in 1911 when it was excised from South Australia.[43] South Australia was founded as a "free province"—it was never a penal colony.[44] Victoria and Western Australia were also founded "free", but later accepted transported convicts.[45][46] A campaign by the settlers of New South Wales led to the end of convict transportation to that colony; the last convict ship arrived in 1848.[47]
The indigenous population, estimated to have been between 750,000 and 1,000,000 in 1788,[48] declined for 150 years following settlement, mainly due to infectious disease.[49] Thousands more died as a result of frontier conflict with settlers.[50] A government policy of "assimilation" beginning with the Aboriginal Protection Act 1869 resulted in the removal of many Aboriginal children from their families and communities—often referred to as the Stolen Generations—a practice which may also have contributed to the decline in the indigenous population.[51] The Federal government gained the power to make laws with respect to Aborigines following the 1967 referendum.[52] Traditional ownership of land—aboriginal title—was not recognised until 1992, when the High Court case Mabo v Queensland (No 2) overturned the legal doctrine that Australia had been terra nullius ("land belonging to no one") before the European occupation.[53]