place american government leaders on trial for their treatment of plains indians, should they be condemned for the way they took the indians land way?

This is a very tough theme, and the main reason for that is the perception, will it be by modern standards, or for the standards of the time when it happened. The way the Native Americans were treated by the American government was terrible in general. They were segregated, didn't had lot of the rights that the white settlers had, lost their lands, were forced to migrate, lot of them were killed etc. All of this by modern standards will fall into the category of violation of the human rights, and the American government leaders would have been convicted for crimes against the humanity. But this didn't happened in modern times, but instead it happened in a period where the people were still constantly in war with each other, conquering or loss of territory was a common thing, and basically it was the law of nature prevailing that only the strongest and fittest will survive. Also, it has to be taken in consideration that it is not only the American government that took land away from the Native Americas, but the different tribes were very often in war with each other, and they were conquering and taking over lands from each other, so by that logic they should be condemned as well, as it is the same principle.