"The morning of January 12, 1888, was unusually mild, following a punishing cold spell. It was warm enough for the homesteaders of the Dakota Territory to venture out again, and for their children to return to school without their heavy coats—leaving them unprepared when disaster struck. At the hour when most prairie schools were letting out for the day, a terrifying, fast-moving blizzard blew in without warning. Schoolteachers as young as sixteen...