I think we keep making the mistake of seeing history through our 'enlightened' eyes and not the eyes of the past.
Take slavery, for instance. Slavery was around for thousands of years and actually made a lot of sense for those times because it was actually thought of as merciful compared to the alternative for nations that were not developed enough to stand against more powerful ones. I mean anyone who was not enslaved after their land was taken over would otherwise be killed right? So while we might wag our heads at the idea, it was an improvement over the previous killing solution.
Now the treatment of Native Americans is a bit of a sad story too, but if we look at it in context with what was happening it was really the first time one group of people from a completely different continent had ever come into a different land and even tried to accomodate one another. I mean think about it, when in history did a bunch of Romans, Greeks, or Mongolians ever come over in a big group to another land and say, "Hey guys would it be cool if we lived here?"
I mean especially with having really superior technology and such. Up to that point it was one empire against another in a big game of risk to see who would out-compete the other empire so the very idea that they even tried to come in peace and hang together and smoke the odd peace pipe was actually a lot of progress.
And because it was a new scene it was like anything else people have ever tried: prone to screw-ups. I mean think about how little misunderstanding it took to provoke a war. I read once about a tribe near the New England states that made friends with the local commander of the guerrison, but then he got sick and was replaced by a new guy from England. They had no Web back then so he had no idea who these guys were who were camped outside his fort. So when a different tribe from a bit up the river came by and stole some of the horses belonging to the army he naturally got confused about who did it and retaliated against the wrong tribe.
Stuff like that caused by completely different languages and customs led to a lot of stories of atrocities on both sides that were probably exaggerated. So nobody could really say one side was perfect and the other scum because everyone was after different things. Some would try their best for months only to have a misunderstanding undo it all in a minute.
But still it was progress and the fact that we feel bad about it is a sign that we've learned from our past. That's never a bad thing as long as we know when to stop taking the blame.
