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My mother grew up in North Dakota which is close to the Canadian border. She told me that the way she had been taught by her elder relatives was, that when Catholics were on their way to Church to go to confession the day before All Saints' Day, Protestants (who enjoyed playing pranks on Catholics as part of their taunting them for their faith) would hide in the bushes and jump out pretending to attack them, so as to frighten Catholics. It became more effective to wear scary costumes which in the dim evening autumn light tend to have a more sinister appearance. Catholics were vulnerable because they had an abiding desire to get to confession, lest they would not be able to receive Communion the following day, a Feast Day. The pranksters did things like tip over outhouses with an occupant inside, or demand some kind of "treat" lest they would continue with their mischief, thus the saying, "Trick or treat!" So the Catholics started carrying trinkets or candies that they could offer to the Protestants to satisfy their demands.
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Her recent ancestors (19th cent.) had been in New England but were chased and persecuted by Huguenots (from France apparently) so they moved to Canada. It wasn't a matter of just being chased and harassed one day a year. It was an every day affair, but the end of October was a particularly troublesome time, perhaps having to do with "Reformation Day," which is October 31st, the day Martin Luther had nailed his 95 Theses on the door of the Wittenburg Chapel in 1517, which was how the Huguenots got started. There were other Protestants in Canada that made life unbearable so they moved west, and eventually moved south from Canada into North Dakota. So their family history was driven in a large part by religious persecution, and suffering for their faith. Her mother was Irish and English and her father was German, both cradle Catholics.
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I don't have any reason to doubt her explanation. She had 3 brothers and 4 sisters, all of whom told the same story. The eldest sister became a nun, and all 8 siblings remained fervent lifelong Catholics. So were they all making it up? I'm not saying this must have been the entire story of how Halloween developed, but if she said that she had been told this is what had gone on, was someone just making history up to see if they could fool everybody?
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It's a well-known fact that Halloween is an American phenomenon, and in Europe nobody practices it. Yet there are pagan practices in Europe in which October 31st is a day of prominence because that's the day when the veil of separation between our world and the preternatural world is the thinnest, therefore spells and witch's incantations have a greater effect on that day. Lutherans don't appreciate the association, but it's none the less real.
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