”September Dawn” graphically dramatizes the controversial real-life massacre of 120 men, women and children traveling through Utah in the nineteenth century. The Mountain Meadows Massacre, as it is known, occurred on September 11, 1857, and was the first known act of religious terrorism on U.S. soil. A group of Mormons, many disguised as Paiute Indians, slaughtered all but 17 small children on a wagon train on its way to California. One man, the adopted son of Mormon leader Brigham Young, was eventually executed for the crimeÂ—20 years after the event. Woven into this real-life background is the Romeo and Juliet story of a young Mormon man who falls in love with a beautiful girl on the wagon train.