Ah, Halloween. A night full of free candy, cheap costumes, and grinning pumpkins. The holiday is an American custom important to many these days, but it was originally celebrated as a harvest festival by the Celts in Ireland. However, the meaning of the holiday and the intentions behind Halloween celebrations have changed over time.

According to The Library of Congress, the Celts celebrated Samhain (pronounced SOW-in) on November 1. It marked the beginning of the Celtic year, but it was also supposedly the day when the souls of the dead were capable of communing with the living. People lit bonfires and made sacrifices to guide the souls of the recently deceased to the afterlife.

After Christian missionaries made it to Ireland, they converted many Celts to Christianity, though they were not able to completely abolish Samhain. In an effort to wipe out the pagan practice, they replaced it with All Hallow’s Day, a feast to celebrate all Christian saints. But the spirit of Samhain lived on in the celebrations that took place the day before All Hallow’s Eve, a time when wicked spirits were said to roam the earth. To keep them away, people appeased them by leaving out food and drink, as well as certain items said to protect households against malicious entities. Naturally, people started impersonating spirits to eat the free food that people left out, and it became a custom to dress up in elaborate costumes. In the mid-1800’s, Irish immigrants fleeing the Irish Potato Famine of 1846 brought the holiday to the U.S., and in the late 1800’s, it became incredibly popular. The first official Halloween celebration was held in Anoka, Minnesota, in an effort to keep children from engaging in pranks.

Another popular Halloween tradition and a staple of modern-day Halloween festivities, the practice of carving Jack O’Lanterns, comes from an old Irish tale of a man named Jack (no surprise there). According to History.com, Jack supposedly convinced the Devil to climb a tree to grab him an apple, but while the Devil was in the tree, Jack carved a cross into the trunk. In Christian religions, the cross can’t be crossed by the Devil, so the Devil could not escape the tree. Jack only let the Devil out after he promised to leave Jack’s soul alone after death.

After Jack’s death years later, legend has it that God would not allow him into Heaven, since he had made a deal with the Devil. The Devil, true to his word, didn’t allow Jack into Hell. Jack’s soul wandered the earth for the rest of eternity, lighting his way with a carved turnip that contained a burning ember. When Irish immigrants came to the U.S, they brought with them the practice of carving turnips for Halloween. Soon, people realized that pumpkins are easier to carve, and the modern-day Jack O’Lantern came into being.

Nowadays, the spirit of Halloween is less harvest festival of the dead, and more hard candy and creepy clowns, but it’s definitely still got the same basic underlying meaning: a night where friends and neighbors can come together for a celebration of all things wicked. Happy Halloween!