>And exactly where do you think the entire state of Illinois and Maine or any state came from? They weren't just sitting uninhabited waiting for your arrival :o) Look at every country in the world and find a handful whose residents were the original inhabitants and didn't end up there by virtue of conquering the locals or running from their land when it was conquered.
Not necessarily and not in every case. It used to happen that a conquering army would just run out the previous conqueror and stay there, and unite with the previously occupied peoples to defend the land together. The one case I know of are the Hungarians and the Kuns - there wasn't enough of each of them to create a problem, there was enough land. But that was in the single digit centuries. The population was sparse and it was even possible that two migrations would just pass each other without knowing of each other.
Though I'd still keep any culture responsible if it expanded at the expense of others, if it had the audacity to call itself civilized.