From The Writer's Almanac:
Today is Halloween, one of the oldest holidays in the Western European tradition.
Today, 70 percent of American households will open their doors and offer candy to strangers, most of them children; 50 percent of Americans will take photographs of family or friends in costume; and the nation as a whole will spend more than six billion dollars. In terms of dollars spent, it is the second most popular holiday of the year in this country, after Christmas.
For the Celtic people of Northeastern Europe, November 1st was New Year's Day, and October 31 was the last night of the year. Celts believed it was the night that spirits, ghosts, fairies and goblins freely walked the earth. Archaeologists aren't entirely sure what all the traditions were, but they believe the holiday involved bonfires, dressing up in costumes to scare away evil spirits, and offering food and drink to the spirits of family members who had come back to visit the home.
It was Pope Gregory III in the eighth century A.D. who tried to turn Halloween into a Christian holiday to divert Northern Europeans from celebrating an old pagan ritual. He made November 1st All Saints Day, and October 31 became All Hallows Eve. Instead of providing food and drink to the spirits, Christians were encouraged to provide food and drink to the poor. And instead of dressing up like animals and ghosts, Christians were encouraged to dress up like their favorite saints.
In the United States, Puritans tried to outlaw Halloween, in part because of its association with Catholicism. So it was the Irish Catholics who brought Halloween to this country, when they immigrated here in great numbers after the potato famine in the 1840's. Since the Irish were largely poor and oppressed, Halloween became a holiday for them to let off steam by pulling pranks, hoisting wagons onto barn roofs, releasing cows from their pastures, and committing all kinds of mischief involving outhouses. Treats evolved as a way to bribe the vandals and protect homes.
But by the late 1800's, Victorian women's magazines began to offer suggestions for celebrating Halloween in wholesome ways, with barn dancing and apple bobbing. And by the early 20th Century, it became a holiday for children more than adults. In 1920, the Ladies' Home Journal made the first known reference to children going door to door for candy, and by the 1950's it was a universal practice in this country. By 1999, 92 percent of America's children were trick-or-treating.
What's interesting about Halloween is that it has no real connection to the majority religion of this country, it does not celebrate an event in our nation's past, it does not involve traveling to visit family, and it doesn't even give us a day off work. But it gives us the chance to try out other identities. For one day, people can feel free to dress as the opposite gender, as criminals, as superheroes, celebrities, animals, or even inanimate objects. But Halloween retailers report that the most popular costumes remain some variation on witches, ghosts, and devils.