History is never as simple as it appears. For Instance, many indians did fight and help the colonists in 1776.
In the Creek War of 1814, 800 Cherokee volunteers led under Major Ridge fought the Creek along side Andrew Jackson. Some say a Cherokee brave saved Jackson' life. He thanked them by demanding land concession after the war was over from the Creek and the Cherokee.
This speaks against the notion of "peaceful indians". They weren't. And note also that one of the great indian leaders, Tecumseh, is considered a great indian leader because he actually managed to unite a number of tribes, managed to get them to stop fighting each other, and got them all lined up to support the British against the Americans.
I recognize that it wasn't simple, and that in many cases there were (some) indians on either side. But by and large the native population was trying to stop Americans at every step along our way. Guess they paid the price for that.