I fail to see why the continued existence of crime in societies which value liberty means that liberty is defunct. Anyone who has given politics some thought deems liberty as good everyone, unless the person in question has the sole purpose of doing good only for his despotic leaders.
Most native americans were assimilated into the settler's economy when they arrived, first through trade and then through actually cultivating tracts of land with white settlers aswell as marrying them and this continued long after 1775. It was those that were further away from the east coast were attacked by criminals, not by the government, they then retaliated against peaceful settlers who complained to the government who then set about subjugating them prompting further attacks. The government was more occupied with development and many of the revolutionaries who kicked the British out had an obsession with native americans and saw their culture as part of the grounding for a new American culture. The killings were instigated by whites, but by white criminals. If europe was populated by native americans and america was populated by hunter gatherer whites the same thing would have happenned, the determinning factor here is whether the person who saw native americans approaching his hut was a criminal or not. I doubt this person was a libertarian idealist or shot them because he was white or an american. He shot them because he was an idiot. Much like gang killings in Detroit are not perpetrated by people because they are black, but because they are idiots and liberals.
However Stalin starved and executed 20 million people intentionally because he believed in socialism and the same thing will happen if we let them get into power.