Day of the Dead, or Día de los Muertos, is an ever-evolving holiday that traces its roots back 3,000 years to rituals honoring the dead in pre-Columbian Mesoamerica. The Aztecs placed skulls on altars to honor and commune with their dead; the Mayans made figures containing the ashes of the dead and brought them offerings on festival days. Two thousand years ago, the Celts celebrated Samhain in the fall, when the veil between the living…