In 1692 Puritan Samuel Sewall sent twenty people to their deaths on trumped-up witchcraft charges. The nefarious witch trials in Salem, Massachusetts represent a low point of American history, made famous in works by Longfellow, Nathaniel Hawthorne (himself a descendant of one of the judges), and Arthur Miller. The trials might have doomed Sewall to infamy except for a courageous act of contrition now commemorated in a mural that hangs beneath...