Halloween originated from an ancient Celtic festival. During Samhain people would light bonfires and wear costumes to ward off evil spirits. All Saints' Day was also called All Hallows and the night before, when the traditional Samhain festival used to take place in Celtic regions, was called All Hallows Eve. This practice was believed to have started over 2,000 yrs ago. . Immigrants from Scotland and Ireland brought the holiday to America in the 1900s. Halloween costumes started to appear in stores in the 1930s