Halloween originated from the ancient Celtic festival of Samhain, marking the end of the harvest season and the beginning of winter. Traditionally, Celts believed spirits could cross over from the dead on this day. The traditions of wearing costumes and carving jack-o-lanterns come from an Irish legend about a man named Stingy Jack. Now, children dress in costumes and go trick-or-treating from house to house on October 31st, receiving candy and other treats. Popular Halloween symbols include pumpkins, ghosts, witches, and black cats.