Why Do We Celebrate Halloween? The Surprising History Behind Our Favorite Spooky Traditions

Ever wonder why we dress up in costumes and go trick-or-treating every October? It turns out the Halloween we know and love today has a long and fascinating history that’s a mix of ancient festivals, spiritual beliefs, and even some clever marketing.

The story starts with the Celts, who lived over 2,000 years ago in what is now Ireland and the United Kingdom. Their year ended on October 31 with a festival called Samhain (pronounced "SAH-win"). This wasn't just the end of summer; it was a time when they believed the veil between the living and the dead became thin. Ghosts and spirits were thought to return to Earth, and to protect themselves, people would light bonfires and wear costumes made from animal skins to either scare the spirits away or blend in with them.

They'd also leave food and drink out to appease the roaming ghosts.

As Christianity spread, the church sought to replace these pagan festivals with its own holidays. Pope Gregory III designated November 1 as All Saints’ Day, a day to honor all saints and martyrs. The night before, October 31, became All Hallows’ Eve, which eventually evolved into "Halloween."

Over the centuries, these traditions blended together, creating the holiday we recognize today:

• Costumes: That costume you're planning? It's a direct link to the Celtic tradition of disguising oneself to ward off spirits.

  
  

• Trick-or-Treating: The roots of this custom can be traced to a medieval practice called "souling," where the poor would go door-to-door, offering prayers for the dead in exchange for "soul cakes." In Scotland and Ireland, children would perform songs or tell jokes for a treat—a practice known as "guising."

  
  

• Jack-o'-Lanterns: Carving spooky faces into gourds originated in Ireland, where people used turnips and potatoes to ward off evil spirits. When Irish immigrants came to America, they discovered that pumpkins were much easier to carve, and the tradition stuck.

  
  

So, the next time you're picking out a pumpkin or choosing a costume, you'll know you're taking part in a celebration that's part Celtic festival, part Christian holy day, and completely American fun.