Halloween in the United States is often assumed to be American in origin. It is not. It arrived with people — specifically with Irish and Scottish immigrants in the nineteenth century — and what America did was take a rural, half-religious folk custom and turn it into a national festival with an industry attached.
What arrived
The festival that landed was already ancient. Samhain marked the end of harvest and the start of winter in Gaelic Ireland and Scotland, a threshold night when the boundary between worlds was thought to thin. The Church laid All Hallows' Eve over it, giving the evening its name.
Irish and Scottish emigration, hugely accelerated by the Great Famine of the 1840s, carried the whole bundle across the Atlantic: the disguises, the door-to-door begging, the lanterns, and a great deal of fortune-telling.
In the old country, going out disguised on the night the dead walked was sensible precaution. In America it became a costume party — but the logic underneath is still there every time a child puts on a mask.
The pumpkin is the American contribution
The one genuinely American change, and it happened almost by accident.
In Ireland and Scotland the Halloween lantern was carved from a turnip, a swede or a mangelwurzel — dense, pale, brutally hard work, and considerably more frightening than what replaced it. Surviving examples in Irish museum collections look like shrunken heads.
America had the pumpkin: native to the continent, enormous, soft, hollow, and ripening at exactly the right moment. It is simply a better lantern. Within a few generations the turnip was gone everywhere except a few corners of Britain and the Isle of Man.
So when people say the pumpkin is the symbol of American Halloween, they are right — it is the part America actually contributed.
Trick-or-treat was assembled here
The two halves came from different places and fused in America.
The treat is old and European: souling in England, where the poor called at houses offering prayers for the dead in exchange for spiced cakes, and guising in Scotland, where children performed a song or joke before being paid.
The trick is closer to American mischief-night traditions, which by the 1920s and 30s had got seriously out of hand — vandalism in cities was severe enough that communities organised alternatives specifically to redirect it.
"Trick or treat" as a phrase and a bargain appears in the 1920s and 30s and spreads nationally after the Second World War, helped enormously by a confectionery industry that understood exactly what it had been handed.
Then America exported it back
The version the world now recognises — costumes off a peg, plastic pumpkins, doorbell rounds, haunted attractions — is the American one, and from roughly the 1980s it travelled back to Britain, into Europe, and beyond.
Which produces the odd situation where British people complain that Halloween is an American import. The trick-or-treating in its current form fairly is. The festival is not; it left from their own ports.
What America built on top
The single biggest American addition is not a custom at all — it is an industry. The haunted attraction business, which barely exists in most countries, runs to thousands of professional attractions in the US, employing tens of thousands of actors, designers and technicians each autumn.
Some of it grew out of Jaycees charity haunts in the 1970s; some out of theme parks, where Knott's Scary Farm ran the first event of its kind in 1973 and every park since has copied the template.
That is a genuinely new thing, and the rest of the world is still catching up with it. You can see the whole scale of it in our directory.