Halloween History: From Samhain to Trick-or-Treating

Samhain: The Celtic New Year That Opened a Door to the Dead

Halloween, as the name suggests, began as a contraction of “All Hallows’ Eve,” but its story starts long before that name existed. According to the reconstruction most historians favor, though Encyclopedia Britannica frames the link more cautiously than other sources, saying the holiday “may have originated” this way, Halloween’s roots reach back to Samhain, the festival Celtic peoples across west-central Europe held around October 31. The Celts, who according to HISTORY had settled that region roughly 3,000 years ago, marked their new year and the start of winter on November 1; Samhain was the night that opened it. World History Encyclopedia instead dates the Celtic arrival in Ireland to roughly 2,500 years ago, a different figure that isn’t necessarily inconsistent with the first, since it covers a narrower time and place.

That night, according to the beliefs the sources attribute to the Celts, the line between the living and the dead grew thin, and spirits found it easier to cross between the two worlds. Druid priests performed rites and lit bonfires to push back the dark and ward off anything supernatural, throwing the bones of sacrificed animals into the flames, a detail that, per World History Encyclopedia, may be behind the popular etymology of the English word “bonfire,” literally a fire of bones. People wore masks, old clothes or costumes made from animal hides, not for fun but to blend in with visitors from the other world. The festival, the same source notes, probably lasted three days.

The Church Names the Night

The shift from a pagan festival to a Christian one is better documented. In 609 CE, Pope Boniface IV dedicated the Pantheon in Rome to Christian martyrs. It was Pope Gregory III, whose papacy falls in the 8th century, who later extended the observance to every saint and moved it from May 13 to November 1, the same date as the Celtic new year. By the year 1000 CE the Church had also established November 2 as a day set aside for the dead.

The night before, still tied to Samhain in popular memory, became known as “All-Hallows Eve,” “the eve of all the holy ones,” contracted over the centuries into “Halloween.” Britannica notes that the choice of date served, at least in part, to replace a pagan holiday with a Christian observance, a reasonable inference rather than something the period’s sources document directly. A similar pattern, a Christian date layered on top of a pre-Christian custom, shows up in the history of Christmas, where December 25 inherits rites and symbols from the Roman Saturnalia and the Norse Yule.

Jack’s Lantern: From Turnip to Pumpkin

No Halloween symbol has a more misunderstood history than the carved pumpkin. According to Irish legend, a man known as Stingy Jack invited the Devil for a drink and, to avoid paying, talked him into turning into a coin; Jack pocketed it next to a silver cross, which kept the Devil from changing back until he promised to leave Jack alone for a year and never claim his soul. Later Jack tricked him again, getting him to climb a tree and carving a cross into the bark so the Devil was stuck up there until he agreed to leave Jack alone for another ten years. When Jack eventually died, the story ends with a double rejection: heaven wouldn’t take him because of how he had lived, and hell wouldn’t take him because the Devil had given his word. He was tossed a single burning coal from the flames of hell, and Jack placed it inside a hollowed-out turnip to light his way as he wandered forever between the two worlds, which is, quite literally, how the first “Jack-o’-lantern” came to be.

In Ireland and Scotland, turnips, not pumpkins, were the vegetable of choice for this: people hollowed out a menacing face and set it on a windowsill or by the door, a way to scare off Stingy Jack himself and other night-time visitors. The sources agree on one specific point: pumpkins weren’t native to Ireland, while turnips were. It was Irish and British emigrants who carried their vegetable-carving custom with them when they reached the United States, shifting it onto the pumpkin, which was available there and not back home, and turning a generic autumn pastime into a custom tied specifically to Halloween.

Practical example: picture an Irish family newly arrived in North America in the mid-1800s and the shift from turnip to pumpkin becomes easy to see: the act of hollowing out a vegetable to make a lantern stayed the same, only the raw material changed, to something more plentiful and easier to carve.

Checking where a popular symbol actually comes from, instead of settling for the most repeated version, is the same exercise worth doing with other traditions people assume are older or more “authentic” than they really are, the same thing happens with the real history of carbonara, a dish whose popular legend and documented facts tell two different stories.

Trick-or-Treating: A Tradition Older Than It Looks

Trick-or-treating also has a longer history than its modern form suggests. In the Middle Ages, people practiced “mumming”: dressing up as ghosts, demons or other creatures and performing skits or tricks in exchange for food and drink. As Christianity spread, “souling” emerged: poor people visited wealthier households and received treats called “soul cakes” in exchange for a promise to pray for the family’s dead. In Scotland and Ireland, “guising” developed instead: young people dressed up and received small offerings after singing a song, reciting a poem or telling a joke, a “trick” standing in for the prayer that souling called for.

Practical example: picture a Scottish teenager in the late Middle Ages knocking on a door and reciting a poem for a bit of food, guising, and it’s easy to see the direct line to what, centuries later, would be called trick-or-treating: the setting changes, but the trade of a small performance for a reward stays the same.

Guising and souling reached North America mainly with Scottish and Irish immigrants starting as early as the late 19th century, alongside the larger wave of emigration tied to the Great Famine of the 1840s. By the 1920s, though, pranks by young people had become the main activity of Halloween night, often edging into vandalism, a problem the Great Depression made worse. One theory holds that this very excess pushed communities, in the 1930s, toward an organized, community-based tradition instead: trick-or-treating in the form that endured. The term and the practice spread widely around the Great Depression years, only to be interrupted by World War II: with sugar rationed, there wasn’t much candy to hand out. The custom only became widespread again with the postwar baby boom.

For anyone wondering where the calendar behind all these dates, including Halloween’s, comes from, the history of month names traces the Roman origins of the calendar still in use.

The Numbers Behind a Billion-Dollar Holiday

Halloween, brought to the United States mainly by 19th-century Irish and Scottish emigrants, has since grown into a sizable commercial event as well. According to the survey Prosper Insights & Analytics conducted for the National Retail Federation among more than 8,000 U.S. consumers, expected spending for Halloween 2025 reached a record $13.1 billion, with record average spending of $114.45 per person.

Within the 2025 forecast, costumes account for $4.3 billion (bought by 71% of consumers), decorations for $4.2 billion (78% of consumers, up from 75% in 2024) and candy for $3.9 billion; another $860 million goes to pet costumes. 73% of consumers said they planned to celebrate in 2025, roughly in line with 72% the year before, while 79% of shoppers expected higher prices because of tariffs. A holiday that, according to the most widely accepted reconstruction, started out as a Celtic agricultural new year, and that later passed through a papal decree and an Irish legend about a man who outwitted the Devil, is in 2025 also measured in billions of dollars of costumes and decorations: from the druids’ bonfires to consumer spending surveys, with centuries of Christianization and emigration in between.