Sand Creek was truly the worst Indian massacre in the history of this country. In most others there were misunderstandings (Wounded Knee) or larger conflict (Washita River). Sand Creek was an atrocity, as clear of one as there was in the history of the West.
Well, there were some out in CA and OR that were pretty bad, too, but I believe all of those were carried out by unorganized militia, in other words, mobs.
There were also some horrible ones in colonial times.
But the actual US Army behaved fairly well in this regard throughout its history.
***Sand Creek was truly the worst Indian massacre in the history of this country. ***
Does it beat Fort Mims? How about the masacres at Ft Dearborne where an entire generation of white children were murdered? Does it beat the Conspiracy of Pontiac?
There were worse massacres. In one massacre over four hundred indians were killed by the evil attackers.
Oh by the way, the attackers were also Indians. Hopi vs Navajo wars.
And if you want one before the White Man showed up on the scene here is this link.
http://www.dickshovel.com/scalp.html