Halloween has its origins in ancient Celtic traditions, particularly the festival of Samhain (pronounced "sow-in"), celebrated over 2,000 years ago in what is now Ireland, the UK, and northern France. The Celts marked November 1 as the beginning of the new year, and Samhain was a celebration on October 31, the night before. It symbolized the end of summer and harvest and the beginning of winter, a time often associated with death due to the harsh conditions.
During Samhain, it was believed that the boundary between the living and the dead blurred, allowing spirits to roam the earth. To ward off these spirits, the Celts would light large bonfires, wear costumes (often animal heads and skins), and leave food offerings to appease roaming ghosts and other supernatural entities.
When Christianity spread, many pagan festivals were either transformed or replaced with Christian observances. In the 8th century, Pope Gregory III established November 1 as All Saints' Day, a day to honor saints and martyrs, while October 31 became known as All Hallows’ Eve. Over time, this evolved into what we now call Halloween.
By the 19th century, European immigrants brought Halloween traditions to North America, especially the Irish and Scottish, who celebrated with costumes, parties, and even some lighthearted pranks. These traditions merged with others, creating a distinctly American version of Halloween with its focus on trick-or-treating, costumes, and community festivities.