Australia was populated by a dispersal of humans who left Northeast Africa, sometime around 50,000-100,000 years ago. This dispersal was probably not a case of planned expeditions like the European colonization, but rather small movements of hunter-gatherer-fisher communities played out over prolonged time periods. This "dispersal of humans" became known as the Australian Aborigines/Aboriginals or "black" Australians. Similar to the segregation seen in the Unites States during and after the era of the slave trade, a large history of mistreatment dating back to the 1800s is found in the history of the Aboriginals in Australia. Perhaps the saddest bit of history in the unfair treatment of Aboriginals is that of the Stolen Generation. 
This term is used to describe those children of Australian Aboriginal descent who were removed from their families by the Australian Federal and State government agencies and church missions, under acts of their respective parliaments. According to federal policy, the Stolen Generations were taken from their homes and communities ‘for their own good’. Some white Australians believed that it would be beneficial for Aboriginal children with some ‘white blood’ to grow up in a white society. The goal was to eventually assimilate all Aboriginal children into white society. While it is unclear exactly how many children were taken from their homes, some estimate that the numbers could be between 1/3 and 1/10 of all indigenous Australian children born during that time.
On February 13th, 2008, Prime Minister Kevin Rudd used time in Parliament to apologize to the Aboriginals for the way they had been treated in the past, with a special segment of his apology directed those part of the Stolen Generation. However, this was not the first time an apology had been proposed. During the term of former Prime Minister John Howard, many urged him to issue an apology for the previous treatment of indigenous Australians. Howard refused for over a decade to apologize to the Stolen Generations - a stance supported, polls suggest, by about 30% of Australians. Those in opposition feel that the Aboriginals should be thanking the government for removing their children from their homes and giving them, essentially a "white" upbringing. Most Australians, however, did not and do not condone the mistreatment of the Aboriginals and applauded Rudd following his formal apology. Here are some useful links:
Prime Minister Kevin Rudd's apology
Reactions to the apology
BBC News article following Rudd's 2008 apology
More information on the "Stolen Generations"
