where did halloween originate

Halloween originated from the ancient Celtic festival of Samhain, which was celebrated around November 1st. This festival marked the transition from autumn to winter and was believed to be a time when the boundary between the living and the dead was blurred, allowing the souls of the dead to revisit the living world. People celebrated by lighting bonfires and wearing costumes to ward off ghosts. Later, in the eighth century, the Christian feast of All Saints' Day on November 1st incorporated some of Samhain's traditions, and the evening before became known as All Hallows' Eve, eventually shortened to Halloween. This origin is primarily linked to the Celts in ancient Britain and Ireland, and the customs spread to the United States with Irish immigrants in the 19th century, where Halloween evolved into the secular celebration known today.