(REUTERS/Stoyan

(REUTERS/Stoyan Nenov)

Most of us carve pumpkins, dress up and go trick-or-treating on Oct. 31, but, what is the history of Halloween and why do we do all of these things?

We follow all of these Halloween traditions each year but many of us have no idea what they actually mean or where these traditions came from.

Here's a look at the history of Halloween and an explanation for why we carve pumpkins, dress in costumes, and trick-or-treat.

Origins

Halloween celebrations date back some 2,000 years to what is now Ireland. Originally a two-day holiday, ancient Celtics marked Oct. 31 as Samhain, signaling the end of harvest time. They also celebrated Nov. 1 as the beginning of a new year.

The Date

Halloween was originally a pagan holiday for which the dead were honored.  The holiday is celebrated on Oct. 31 because it was the last day of the Celtic calendar. By the 8th century, the Celtic holiday had merged with the Catholic feast of All Martyrs Day, and finally created the true All Hallows Eve, or Halloween.

Masks and Costumes

Ancient Celts believed that on the night before the New Year the boundary between the worlds of the living and the dead was blurred. Because it was believed that spirits and ghosts came back to earth on Halloween, costumes were worn to trick the beings into believing they were among fellow spirits.

Witches

Centuries ago, witch meant wise one and people believed that witches told fortunes and flew out of chimneys on broomsticks.

Jack-o-Lanterns

This tradition comes from an old Irish folk tale about a notorious drunkard and trickster named Stingy Jack. As the story goes, Jack was unable to get into heaven because of a trick he played on the devil. Denied entrance in both Heaven and Hell, Stingy Jack was forced to forever roam in the frigid darkness. According to the folk tale, the devil gave Jack a single ember to light his way, which he placed in a hollowed-out turnip to keep it glowing longer.

When the Irish immigrated to the U.S. during the Great Potato Famine of 1845-1850, they found that turnips were not as readily available like they were in their homeland. They began carving pumpkins as a replacement to carry on the tradition.

Bobbing for Apples

The Romans brought apple trees when they conquered Britain. The apple was representative of the goddess Pomona, the goddess of fruit. Because Pomona was a fertility goddess and because the Celts saw the pentagram as a fertility symbol, they believed that the apple could be used to determine marriages. From this belief comes the game of bobbing for apples. During each annual celebration, unmarried people would try to bite into a floating apple and the first person to bite would be the first to marry in the New Year.

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Trick-or-treating

On Halloween, Irish peasants would beg the rich for food and coins. For those that refused, they would play a practical joke. To avoid being tricked, the rich would hand out cookies, candy, and fruit - a practice that morphed into the trick-or-treating of today. The trickery was once a major part of the American celebration, but a move in the late 1800s to make the holiday more family-friendly and community-centered brought a shift away from the tricks and toward the treats.

Trick-or-Treat - phrase

Before the 1940s, very few Americans had ever used the words trick-or-treat. The saying caught on after World War II. Typically, treats were not candy but popcorn balls, nuts, apples, and coins. Trick-or-treat really took off in the 1950s as a marketing scheme by candy companies promoting their products for the Halloween festivities.

Halloween vs. Dia de los Muertos

Initially, the Mexican custom of El Dia de los Muertos (the Day of the Dead) bares a striking resemblance to U.S. version of Halloween. While Dia de los Muertos begins at midnight on Oct. 31 and features an abundance of images related to death, the customs have different origins. Typically, Halloween festivities show death as something to be feared, while Dia de los Muertos celebrates the memories of those who have died.

More Fun Facts about Halloween

Americans spend more money on Halloween than any other holiday, except Christmas.

The Count Dracula Society was founded in 1962.

Black and orange are the official colors of Halloween - orange for the fall harvest, and black for darkness and death.

Reese's Peanut Butter Cups are consistently ranked the most popular Halloween candy.

Americans will spend about $2 billion on Halloween candy this year.