I'd suggest you take your own advice, because it's clear that you know very little about what happened to the natives in North America. In lands that had not been settled yet, the only converting going on was NOT by force, it was done by missionaries in essentially the same way it happens today. After the US had settled lands, there were natives still living on that land. The government and people at the time looked for a way to either move them away or assimilate them. Yeah there were shitty practices, for sure. But expansion wasn't done with the INTENT of destroying/converting the natives, unlike in South and Central America. It wasn't even done by military invasion, most of the time. Common US citizens who wanted a plot of land for themselves to build a new life, would move West to the frontier, and work to create it. Conflict obviously followed because that land was already inhabited, and then the US army would come in to protect.. US citizens, what a thought. The local natives rarely stood a chance against the army, and the army clearly considered them to be barbarians considering the way the army treated them, but for the majority of US history there was NOT some mass campaign to annihilate them. If that had been the goal, there wouldn't be any left. They were in the wrong place, at the wrong time, facing the wrong people. Does that make it moral what happened to them? No. But if you consider that the same as conquistadors landing armies on a new continent with the express INTENT of enslaving, conquering, and looting as much gold and treasure as possible to bring home to Spain, then you have very little room to judge morality to begin with.
