I tend to see a lot of people bringing up and even shaming the u.s.a for its treatment of natives during early American history. I was under the impression that all throughout history it was standard for stronger invading forces to either force assimilation of native populations or just kill them if they refused to assimilate. I do not support the actions of our ancestors in these situations, I just want to make sure I have them in the correct context.
US treatment of Native Americans was highly variable, as most of the oppression was done against the will of the federal government. Generally, the Feds would reach an agreement with a tribe but be unable or insufficiently diligent to stop the local governments from doing whatever they wanted. What happened depended on the local policy.
Basically, you could have fun comparing US treatment with US treatment.
First, as a clarification, a lot of the worst instances of mistreatment continued well into the 20th century, which I don't think we can really call "early" American history any more. For instance, the Indian Boarding Schools were only disbanded in the 1920s.
One significant difference, at least at the end of the 19th century, is the racial dimension of social policies in that the "science" of biological racism provided a lot of the justification for mistreatment of Native Americans (among other non-white groups) based on the faulty conclusion that non-whites were biologically inferior rather than pretty much identical genetically and physically as we understand all Homo sapiens is today.
This is of course a huge component of most European colonial policy in the 19th and early 20th century, so it isn't so different from other colonial activities that get rightly lambasted from the same time period. However, this focus on the racial element does contrast these colonial activities with earlier mistreatment of conquered people. There is an element of mistreatment based on blanket physical and social characteristics we call race, rather than solely on your status as a conquered individual. Of course identity was often an important part of treating conquered people prior to the 19th century, but the ideology of racial superiority does focus on that aspect to a much higher degree than many other times, even the early colonial period (such as in 16th and 17th century Spanish colonialism where race was understood more as a social construction than a biological reality, even though it had biological underpinnings).