The Mountain Meadows Massacre (September 7–11, 1857) was a series of attacks during the Utah War that resulted in the mass murder of at least 120 members of the Baker–Fancher wagon train.[1][a] The massacre occurred in the southern Utah Territory at Mountain Meadows, and was perpetrated by settlers from the Church of Jesus Christ of Latter-day Saints (LDS Church) involved with the Utah Territorial Militia (officially called the Nauvoo Legion) who recruited and were aided by some Southern Paiute Native Americans.[2] The wagon train, made up mostly of immigrant families from Arkansas, was bound for California, traveling on the Old Spanish Trail that passed through the Territory.
…
Have you heard, like, anything about Mormanism?
Quick edit:
Like, too many examples for me to possibly list them all, but Netflix made a whole TV show about this one:
https://en.m.wikipedia.org/wiki/Mountain_Meadows_Massacre