Final answer:
The ancient people who observed Samhain and are credited with originating Halloween were the Celts.
Step-by-step explanation:
The ancient people who observed Samhain and are accredited with originating Halloween were the Celts, an ancient culture that inhabited parts of Europe, particularly Ireland, Scotland, and Wales. Samhain was an important Celtic festival that marked the end of the harvest season and the beginning of winter. It was believed that on this night, the boundary between the living and the dead was blurred, and the spirits of the dead would return to Earth.
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