One night, in neighborhoods across America, you will find monsters, ghosts, witches and other characters haunting houses up and down the street. October 31, Halloween, is one of the more popular holidays for children. What child wouldn't want to dress up as a monster or fairy and score a bag of candy in the process?

The origins of Halloween are ancient. 2,000 years ago in the part of the United Kingdom which is now Ireland, the Celts celebrated the beginning of their new year on November 1. As a result, October 31, or Samhain as the Celts called it, was a night to celebrate. The Celts believed that on that one night each year, the wall between the worlds of the living and the dead were easier to cross over and the barrier was thinner. Because of this, they believed that the spirits of the dead returned to the world of the living and caused all sorts of trouble and damage. Since the spirits were present on earth, the Celts believed that their priests, the Druids, were able to make predictions about the future more easily.

Since this celebration was an end to the summer and a beginning to the long, dark, cold, winter the people were hopeful if the Druids were able to make positive predictions for the hard time ahead. After the Romans conquered the British Isles, the Celtic celebration of Samhain was combined with a couple of Roman holidays. Feralia was a day that the Romans honored their dead in late October. The other holiday was in honor of Pomona, the Roman goddess of fruit and trees. Pomona was associated especially with the apple and because of this, the tradition of bobbing for apples may be associated with Pomona after her holiday was lumped in with Samhain and Feralia.

With the spread of Christianity, Halloween was incorporated into a new holiday, All Saints' Day, which was a day to honor saints and martyrs on November 1. This holiday was also called All-hallows or All-hallowmas (which is derived from the Middle English word Alholowmesse, another way to say All Saints' Day). The night before this holiday, October 31, began to be known as All-Hallows Eve and soon, just Halloween. Some time later, the church decreed that November 2 would be known as All Souls Day, a day to honor the dead. It was celebrated much like Samhain, with bonfires, dancing, parades and dressing up in costumes. Together, the three celebrations, the eve of All Saints', All Saints' and All Souls', were collectively called Hallowmas.

The way we celebrate Halloween in America, trick-or-treating, is probably related to the All Souls' Day parades in early England. At this time, the poor would beg for food. They would be given "soul cakes" in return for praying for the family's dead relatives. Eventually, this turned into children visiting neighborhood houses and being given treats such as beer, food and money.

With the new flood of immigrants in the late 1800s, the millions of Irish entering the US helped shape the celebration of Halloween. From Irish and English traditions, Americans began dressing up in costumes and going house to house asking for food or money. By the end of the 19th century, many people began to try to mold Halloween into a holiday that was more about the community and community celebrations than about spirits, pranks or witchcraft. Parents were encouraged to make the parties for their children and families less frightening and attempt to take out the fearful aspects of Halloween.

Today Halloween is the second biggest commercial holiday in America. Americans spend billions of dollars on candy, costumes and parties. Children look forward to Halloween every year, partly because they are able to dress up and be a different person or being for a night, but mostly because of the loot they receive from going door to door in their neighborhood.