To put it into some sort of structure, then consider the way of life as it was and how it was impacted.
Land. For thousands of years a tribe of Aboriginals would go to the same river at the same time of year because a certain fish would be there. This would feed the tribe at that time before both parties continued their journeys. Upon the arrival of the Europeans, the tribe would show up and find that the area was fenced off by white people who told them that the land was now owned by white people and that the Aboriginals were now trespassing. So for continuing to do what they had done for all those thousands of years, some were shot as poachers. And then the white mans cattle would be moved in and that would drive away the indigenous animals and another food source was lost to the Aboriginals and again, if they killed the white man’s animals, then they were rustlers and would be shot. And bit by bit the white man took over everything and claimed it as their own thus prevented the Aboriginals from continuing their transient lifestyles. Previously they were free to move around the land as they desired and then suddenly, all these areas were out-of-bounds to them and they were deprived of access to their food sources.
Spirituality/Belief. The understanding of Dreamtime runs deep and is taught through stories and ceremonies to generation after generation. The respect for all things is a fundamental basis for how the Aboriginals lived their lives. When white people arrived, the Aboriginal understandings were mocked and discarded as primitive and wrong. White people felt that they would help out Aboriginals and teach them the true meaning of spirituality with their Christian teachings. So the basis of Aboriginal beliefs were belittled and ignored and undermined and were continuingly challenged. But the actions that the Christians taught were just a contradiction to the actions they took. Where was the respect of other people and their lives? What about ‘Thou shall not kill’? They were not practising what they preached, but they expected to be listened too as though they were.
Family. The basis of every community of every culture of every land, is family. It is what gives meaning and purpose and guidance and teaching. It makes each individual who they are and provides them with the knowledge to live amongst others. In the case of Aboriginal society, family is strong. Not only that, but family groups are large and all members of a family have a role to play and help with the upbringing of the children and assisting the family using their individual strengths. With the arrival of white people came many murders and arrests and disappearances and the majority of families were affected to some extent by this. On top of that, there were rapes of black women by white men and there started to be more and more half-caste children appearing. But these children were accepted by the Aboriginal families and looked after like any other child. However, white people saw half-caste children as being deserving of a ‘better’ life than the black kids and therefore there started the practice of removing them so that they could be treated white and therefore have a chance to be ‘better’ than the native children. This practice was the start of the stolen generations where children were forcibly removed from their families and sent away from the family in an attempt to make them ‘better’. These children were denied their parents or knowledge of them and so many never found each other again.
The fact is that Aboriginal tribes struggled hugely for a number of reasons when white settlers arrived and through mistreating and disease and the disruption to the black way of life, the communities struggled and it was difficult for them to have enough food. White authorities looked at this and decided that it was the Aboriginals fault that they were struggling and therefore they were doing the right thing to remove children from the conditions that the white man had actually created.