Halloween has its origins in the ancient Celtic festival of Samhain, celebrated over 2000 years ago on October 31st to mark the end of the harvest season and the beginning of winter. The Celts believed it was a time when the veil between the living and the dead was thinnest. They would light bonfires and wear costumes to ward off spirits. When Christianity became dominant in Europe, the Catholic Church merged Samhain with All Saints' Day on November 1st. The night before became known as All Hallows' Eve, which eventually evolved into Halloween. Irish immigrants brought Halloween traditions to America in the 19th century, and trick-or-treating evolved from pranks and vandalism into a