Though Halloween in the U.S. has become synonymous with slasher movies, costumes, and candy, the holiday resulted from the fear of soul possession and ruins.
Halloween originated as the ancient Gaelic harvest festival Samhain, celebrating the "end of summer" and Celtic New Year.
The Gaels believed that the world between the living and the dead was blurred on All Hallow's Eve (October 31), the day before All Saint's Day (November 1), and that evil spirits would return and kill their community's livelihood: their crops.
In an attempt to blend in with these malevolent spirits, the Gaels extinguished the lights, wore masks and scary costumes, and walked noisily in the streets to frighten away the spirits, which might try to posses their bodies.
Even to this day Halloween remains traditional in present-day Ireland, it's place of origin.
Irish children take a weeklong break from school, beginning on the last Monday in October, and families spend the time on festivities.
Houses are decorated with pumpkins and turnips with scary faces, bonfires are lit, and children dress up as ghoulish creatures.
Historians believe that the jack-o-lantern, probably the most recognizable Halloween symbol, comes from an Irish folktake.
According to Irish lore, Jack, a notorious jokester, tricked Satan into climbing into a tree, where he was trapped by a carved cross. Satan promised Jack that he would not tempt him again if he could be freed.
The story goes on to say that after Jack died, he was not allowed into Heaven or Hell. Instead, the devil gave him a light, placed inside of a hallowed-out turnip, to carry through the darkness.
Irish families traditionally carve turnips, but now also carve out pumpkins. When the Irish moved to America, pumpkins were easier to carve and more accessible than turnips.
In preparation for Halloween, most Irish families bake barmbrack, traditional fruit bread used for fortune telling.
After the bread is baked, with special objects placed inside, it is cut into pieces. The fortune is revealed by whatever objects the person finds in his or her slice of bread.
For example, a pea signifies non-marriage, a stick means unhappy marriage, a cloth means bad luck or loss of wealth, a ring means marriage, and a coin signifies wealth and prosperity.
Halloween games in Ireland include bobbing not just for apples with coins inside, but also coins, peanuts or fruit.
Bobbing for apples became a tradition in Ireland when the Romans overtook Celtic property.
Feralia, a Roman festival held in late October, celebrated the Goddess Pomona, the goddess of fruit, who is often symbolized with an apple. It is widely believed that the bobbing for apples game may have come from this festival.
Historians claim the traditions of Halloween came to the United States when the Irish migrated in 1845-1849 during the Irish Potato Famine.
Commercialization of Halloween in the U.S. began in the early 1900s with postcards, and in the 1930s with mass-produced costumes.
According to Bloomberg Businessweek, a National Retail Federation survey revealed that 158 million Americans (66 percent) will spend $6.9 million this year celebrating Halloween.