How did General Miles insult Chief Sitting Bull?

General Miles insults Chief Sitting Bull by giving him a lecture on his tribe's history. He tells him that the Lakota, far from being a peaceable tribe before the white man arrived, were every bit as violent as the white man himself. According to Miles's revisionist account, the Lakota conquered rival tribes on the plains, ruthlessly taking their land and their game from them. As far as the general's concerned, this is no different to what the white man has done to the Lakota.
Sitting Bull bridles at the very suggestion that there is any moral equivalent between what the white man has done and how the Lakota once treated their rivals. He exclaims in response "This is your story of my people." (Emphasis added). The implication here is that Mills doesn't know what he's talking about; he's distorting history to serve the white man's interests. Because he's part of the conquering white race, he's developed a certain arrogance, and therefore thinks he knows more about Lakota history than the Lakota themselves. Thus he feels entitled to give Sitting Bull a lesson about his own tribe's history. This is a prime illustration of the old adage that history is written by the victors.