(CNN)Here is some spooky background information about Halloween, celebrated annually in the United States on October 31. This year, Halloween is on a Saturday.
The word Halloween is an abbreviated version of the phrases All Hallows' Eve or All Hallows' Evening.
Halloween comes from an ancient pagan festival celebrated by Celtic people over 2,000 years ago called Samhain (prono: SOW ehn).
The festival took place in the United Kingdom, Ireland, and northwestern France.
Samhain means "summer's end" and marks the beginning of winter. Samhain is also thought to celebrate the beginning of the Celtic year. The Celts believed that Samhain was a time when the dead could walk among the living.
Trick-or-treating began in areas of the United Kingdom and Ireland. People went house-to-house "souling" - asking for small breads called "soul cakes" in exchange for prayer.
Adults also went door-to-door asking for food and drinks in exchange for a song or dance.
Jack-o'-lanterns are the symbol of Halloween. People in Ireland and Scotland originally used beets or turnips as lanterns on Halloween.
An Irish legend says that jack-o'-lanterns are named for a man called Jack who could not go to heaven or hell and was forced to walk the earth forever with only a coal from hell to light his lantern.
The name jack-o'-lantern can also be derived from the night watchman who would light the street lanterns every evening.
Immigrants from Ireland and Scotland brought Halloween to the United States in the 1800s. Haitian and African immigrants brought voodoo beliefs about black cats, fire, and witchcraft.
Halloween Statistics for 2015:
(ALL from the National Retail Federation)
More than 157 million Americans will celebrate Halloween this year, with eight in 10 millennials saying they are already planning something fun with their friends. Total spending in 2015 will top $6.9 billion, with the average American celebrating planning to spend $74.34 on decorations, candy, costumes and more.
Top Children's Costumes for 2015
1. Princess - 7.2% - 3,199,247
2. Batman Character - 5.9% - 2,634,674
3. Action/Superhero - 5.3% - 2,371,207
4. Animal (Cat, Dog, Lion, Tiger, etc.) - 4.8% - 2,145,377
5. Frozen Character (Anna, Elsa, Olaf) - 4.6% - 2,070,101
Top Adult Costumes for 2015
1. Witch - 9.0% - 4,376,359
2. Animal (Cat, Bear, Gorilla, etc.) - 5.0% - 2,423,830
3. Batman Character - 4.1% - 2,019,858
4. Zombie - 3.9% - 1,918,865
5. Star Wars Character - 2.9% - 1,413,901
Top Pet Costumes for 2015 (no data for # of pets)
1. Pumpkin - 10.6%
2. Hot Dog - 6.8%
3. Batman Character - 4.0%
4. Devil - 3.9%
5. Bumble Bee - 3.7%