Halloween's origins can be traced back to the ancient Celtic festival known as Samhain, which was held on November 1 in contemporary calendars. It was believed that on that day, the souls of the dead returned to their homes, so people dressed in costumes and lit bonfires to ward off spirits.

Samhain (/ˈsɑːwɪn/ SAH-win, /ˈsaʊɪn/ SOW-in, Irish: [ˈsˠəunʲ], Scottish Gaelic: [ˈs̪ãũ.ɪɲ]) or Sauin ( Manx: [ˈsoːɪnʲ]) is a Gaelic festival on 1 November marking the end of the harvest season and beginning of winter or the "darker half" of the year.

Halloween traces its origins to the ancient Celtic festival of Samhain, celebrated on October 31, marking the end of the harvest and the beginning of winter. The Celts believed that on this night, the boundary between the living and the dead is dissolved, allowing spirits to roam the earth.

The most popular event is the Official Salem Witches' Halloween Ball. Hundreds of costumed patrons flock to Salem as fires are burned on hilltops, while witches gather to cast spells for the new year and to honor the dead during Samhain (the ancient name for "Halloween").