This story has been updated.
More than 175 million Americans are slated to participate in this year’s Halloween festivities, according to the National Retail Foundation, and spending is forecast to reach $9 billion, just shy of the record $9.1 billion last year.
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In 2016, according to NRF, total spending hit a record $8.4 billion.
The history of this crazed Halloween holiday and its spooky traditions date back more than 2,000 years.
Here are 7 things you probably never knew about Halloween:
It all started with an ancient Celtic festival.
LEWES, ENGLAND - NOVEMBER 05: Members of the Pheonix Bonfre society walk with burning staffs during the Bonfire Night celebrations on November 5, 2012 in Lewes, Sussex in England. Bonfire Night is related to the ancient festival of Samhain, the Celtic New Year. Processions held across the South of England culminate in Lewes on November 5, commemorating the memory of the seventeen Protestant martyrs. Thousands of people attend the parade as Bonfire Societies parade through the narrow streets until the evening comes to an end with the burning of an effigy, or 'guy,' usually representing Guy Fawkes, who died in 1605 after an unsuccessful attempt to blow up The Houses of Parliament. (Photo by Dan Kitwood/Getty Images)
Halloween’s spooky origins come from an ancient Celtic festival for the dead called Samhain (or “Summer’s End”).
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The Celts, who lived in the region now known as Ireland, the United Kingdom and northern France thousands of years ago, celebrated Samhain on Nov. 1 to mark the end of summer and the harvest and the beginning of a new year, kicking off with the bitter cold winter, a season typically associated with death.
According to History.com, the Celts believed that the night before the new year, “the lines between the worlds of the living and the dead became blurred” and ghosts of the dead returned to earth and ravaged the crops. They also believed the ghosts and “otherworldly spirits” gave Celtic priests, or Druids, a vision into the future.
“For a people entirely dependent on the volatile natural world, these prophecies were an important source of comfort and direction during the long, dark winter,” according to History.com.
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And so, on the eve of Samhain (Oct. 31), Druids built enormous bonfires and the Celts, dressed in costumes made of animal heads and skins, sacrificed their crops and animals to the Celtic gods.
When the Samhain celebrations were coming to an end, the Celts re-lit their hearth fires with fire from the sacred bonfire built by the Druids in hopes that its heat will keep them safe during the coming winter.
Why is it called Halloween?
The moniker comes from Catholicism’s All-hallowmas, a three-day holiday honoring the saints and recently deceased.
During the 7th century, Christianity spread throughout Celtic lands and influenced Celtic religion and popular traditions, including the famous Samhain holiday.
History.com notes “it’s widely believed today that the church was attempting to replace the Celtic festival of the dead with a related church-sanctioned holiday.”
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In the eighth century, Pope Gregory III decreed Nov. 1 All Saints’ Day and the evening before, All Hallows Eve. Nov. 2 later became All Souls’ Day, a day to honor the dead.
The All Saints’ Day celebration was also called All-hallows or All-hallowmas. In Middle English, “Alholowmesse” translates to All Saints’ Day.
The night before All Saints’ Day, which is the traditional night of the Celtic Samhain festival, eventually became known as All-Hallows Eve and later, Halloween.
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Where did trick-or-treating come from?
SYDNEY, AUSTRALIA - OCTOBER 31: A grop of children pose in costume before trick or treating home on Halloween Day in North Bondi on October 31, 2008 in Sydney, Australia. Halloween, also known as Hallowe'en and shortened from its original form of All Hallows' Even, is internationally celebrated on October 31 and originates from the ancient Celtic festival of Samhain, which was a celebration recognising the end of the harvest in Gaelic culture. (Photo by Sergio Dionisio/Getty Images)
The notion of dressing up in costume and going from door to door for goods dates back to the Middle Ages, according to Smithsonian.com.
“Children and sometimes poor adults would dress up [as saints, angels or demons costumes] and go around door to door during Hallowmas begging for food or money in exchange for songs and prayers, often said on behalf of the dead.”
According to Smithsonian.com, back then, it wasn’t called trick-or-treating. It was called “souling” and the beggars were called “soulers.”
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The practice of trick-or-treating emerged in the U.S. in the 1920s and 1930s.
But the earliest known reference to the term “trick or treat” actually comes from a 1927 publication in Canada.
Here’s what the Smithsonian found in the Nov. 4, 1927, edition of the Blackie, Alberta Canada Herald:
“Hallowe’en provided an opportunity for real strenuous fun. No real damage was done except to the temper of some who had to hunt for wagon wheels, gates, wagons, barrels, etc., much of which decorated the front street. The youthful tormentors were at back door and front demanding edible plunder by the word “trick or treat” to which the inmates gladly responded and sent the robbers away rejoicing.”
Still, how exactly Americans adopted the tradition is still a little confusing, History.com reported, though it’s widely understood that Irish and Scottish immigrants brought Halloween traditions to the U.S. with them.
Theorists also say it could have been the excessive pranks on Halloween that led to its adoption as a holiday tradition.
These pranks were popular among “rowdy young people” and often amounted to expensive damage, vandalism and physical violence.
When World War II broke out, however, trick-or-treating came to a halt due to sugar rationing.
Today, Americans spend millions on costumes annually to partake in the door-to-door tradition.
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How did Protestants feel about Halloween?
EISENACH, GERMANY - MAY 04: Protestant clergy, led by pastor Christian Mueller, walk in a procession with a cross to an open-air church service at Wartburg Castle to commemorate the May 4, 1521, arrival of Martin Luther on May 4, 2017 in Eisenach, Germany. Luther, who is known for his 95 theses of 1517 that set the Reformation into motion, lived at Wartburg Castle under protection following his excommunication and translated the Bible there into German. Germany is celebrating the 500th anniversary of the Reformation this year with events throughout the year. The Reformation led to the creation of Protestant denominations all over the globe. (Photo by Sean Gallup/Getty Images)
During Reformation, the holiday came under attack by some Protestants with rigid belief systems who denounced purgatory as a “popish” doctrine.
Purgatory is a Roman Catholic theology that refers to a state between life and death, where one would have to “undergo purifcation” to enter heaven. It’s often regarded as a temporary state of suffering.
As aforementioned, Halloween dates back to the Celtic Samhain festival on Oct. 31, when “the lines between the worlds of the living and the dead became blurred” and spread through Europe as a holiday with traditions for the souls in purgatory.
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The Protestants believe the Bible does not explicitly discuss purgatory and, therefore, rejected it as a biblical belief.
They believed salvation is achieved through faith alone and souls cannot journey from this state of purgatory to heaven.
While many celebrate Halloween on Oct. 31, many rigid Protestants celebrate Reformation Day, commemorating a major period of religious change in Europe and the day German theologian Martin Luther’s proposals were nailed on the doors of a church in 1517.
Today, many contemporary Protestant communities celebrate Halloween as a fun family event.
In his 1998 book, “A Companion to the Lesser Feasts and Fasts,” Christian minister Sam Portaro wrote that Halloween is about using “humor and ridicule to confront the power of death.”
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How did Halloween gain popularity in the United States?
Irish emmigrants sailing to the US during the Great Famine (aka the Irish potato Famine), 1850. Original publication - Illustrated London News - pub 6th July 1850. (Photo by Illustrated London News/Hulton Archive/Getty Images)
Photo: Illustrated London News/Getty Images
It wasn’t until the second half of the 19th century that Halloween really started to gain popularity. That’s due to an influx of Irish immigrants fleeing the Irish Potato Famine.
But due to rigid Protestant belief systems in colonial New England, the holiday wasn’t as popular in those regions.
According to History.com, the holiday and its traditions were much more common in the southern colonies and in Maryland, where folks would tell ghost stories and play pranks.
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What’s up with jack-o’-lanterns?
LONDON - OCTOBER 31: A child enjoys traditional candle-lit Halloween pumpkins on October 31, 2007 in London. (Photo by Peter Macdiarmid/Getty Images)
The origin of the angry orange pumpkin (or jack-o’-Lantern) comes from a Celtic folk tale of a miserly farmer named Jack who constantly played tricks on the devil. His nickname was literally “Stingy Jack.”
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According to History.com, for one of his tricks, Stingy Jack invited the devil to join him for a drink. Once they were together, he pretended not to have any money to pay for his beverage and convinced the devil to turn himself into a coin they could use to buy the drinks.
The devil did so, but instead of paying for the drinks, Jack kept the coin in his pocket, where he also kept his silver cross.
This, he believed, prevented the devil from returning to his original form.
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But eventually, after performing multiple tricks on the devil, Jack died. Legend says God wouldn’t let a man like him into heaven. And the devil, unsurprisingly angry with Jack and his cons, wouldn’t let him into hell, either.
Instead, the devil sent Jack off into the dark night with only a burning coal to light the way, History.com reported. Jack put the burning coal into “a carved-out turnip” and has been roaming the planet since.
Irishmen began to refer to Stingy Jack as “Jack of the Lantern” and later, “Jack O’Lantern.”
Throughout Europe, Englishmen used large beets or turnips or even potatoes to create the lanterns. When immigrants came to America, pumpkins were adopted.
Today, the jack-o’-lantern in pumpkin form is a staple in Halloween decor.
Why are black cats associated with Halloween?
20th July 1934: A black cat crosses the road and in the process holds-up the traffic. (Photo by Fox Photos/Getty Images)
Black cats are another creepy Halloween symbol dating back the Middle Ages, but theorists say their association with Halloween may originate from Puritan pilgrims of Plymouth County, a group that lived a rigid Protestant lifestyle.
Legend has it that witches, who many believed worshipped the devil, would protect their identities by turning themseles into black cats.
The Puritans, along with other strict Protestants, often shunned witchcraft and other Halloween traditions as going against their belief system.
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Unfortunately, due to all of the superstitions around black cats, the creatures have some of the lowest adoption rates and the highest euthanasia rates of all cats, according to Smithsonian.com.
And for decades, many animal shelters have refused to adopt out black cats on or right before Halloween out of fear they will be tortured or sacrificed, according to Gizmodo.
“This is a time when blood rituals take place,” Hedy Litke, director of animal placement at the ASPCA, told K.C. Baker for the New York Daily News in 1999. “Black cats are often sacrificed.”
Learn more about the history of Halloween at history.com.