Two quick points: 
1. This is not rewriting history. The three separate inquiries after Sand Creek all condemned it. Chivington retired so military let it  go. No one knows history anymore. Read the three separate inquiries on line. 
2. Well the town of Chivington is practically a ghost town. You pass it on the way to Sand Creek. It is insignificant while Sand Creek is growing in stature. 
3. The other report by the University of Denver also carried out after Northwestern was even more damning. 
I agree. Don't hide it. Present it.