Complex sentence: On May 21, about fifty Potawatomis and three Sauks from the British Band attacked Davis's settlement, killing, scalping, and mutilating fifteen men, women, and children.
Split into simpler sentences: On May 21, fifty Potawatomis and three Sauks from the British Band attacked Davis's settlement. The Natives killed, scalped, and mutilated fifteen men, women, and children.