On this day 26 years ago, John F. Kennedy Jr., his wife Carolyn, and her sister Lauren vanished into the Atlantic Ocean, capping the 20th century with one more tragedy for the Kennedy family. John Jr.’s death was particularly cruel in its irony. The boy who had captured America’s heart as a three-year-old saluting his father’s coffin died piloting a plane into the dark waters off Martha’s Vineyard. He was heading to a wedding – a celebration that soon became a wake. In less than a century, the Kennedys have lived through more public misfortune, scandal, and sudden death than...