The Mountain Meadows massacre. 1857 A group of pioneers headed for California stopped on land claimed by the Mormons. Some of them were recognized by the locals as men who had attacked the Mormons on their way west, and they slaughtered them, men, women and children.They were talked into giving up their arms for safe passage, then, unarmed, they were all murdered.
I've had Mormons come to my house preaching their religion who never heard of the Mountain Meadows incident. I wonder why.