In Britain the rituals of Hallowtide and Halloween came under attack during the Reformation as Protestants denounced purgatory as a "popish" doctrine incompatible with the notion of predestination. In addition the increasing popularity of Guy Fawkes Night from 1605 on saw Halloween become eclipsed in Britain with the notable exception of Scotland.There and in Ireland, they had been celebrating Samhain and Halloween since the early Middle Ages, and it is believed the Kirk took a more pragmatic approach towards Halloween, viewing it as important to the life cycle and rites of passage of local communities and thus ensuring its survival in the country.
North American almanacs of the late eighteenth and early nineteenth century give no indication that Halloween was recognized as a holiday. The Puritans of New England, for example, maintained strong opposition to the holiday and it was not until the mass Irish and Scottish immigration during the 19th century that the holiday was introduced to the continent in earnest. Initially confined to the immigrant communities during the mid-nineteenth century, it was gradually assimilated into mainstream society and by the first decade of the twentieth century it was being celebrated coast to coast by people of all social, racial and religious backgrounds.
Origin of name
The word Halloween is first attested in the 16th century and represents a Scottish variant of the fuller All-Hallows-Even ("evening"), that is, the night before All Hallows Day. Although the phrase All Hallows is found in Old English (ealra hālgena mæssedæg, mass-day of all saints), All-Hallows-Even is itself not attested until 1556.From Wikipedia