The history of Halloween seems to invite misinformation. The entire holiday is fraught with it. Urban legends breathlessly suggest that children are in danger of being given apples full of razor blades, that there is a vile Satanist lurking behind every mailbox, and that all unfamiliar-looking candy is actually ecstasy, apparently handed out by some poor soul overburdened with too much MDMA lying around. In reality, of course, there is essentially no such thing as tainted candy, and you are roughly as likely to be the victim of human sacrifice as you are to be slain by a meteorite.
Halloween in history is just as murky; it has a few separate origin points that all tie together, and its celebration often cobbles together local customs from preexisting holidays. It definitely owes something to the Celtic festival of Samhain, but it's hard to say with certainty what customs come from where; a lot of the only written records come from the Romans, who considered every non-Roman a wild-eyed barbarian maniac. We can at least be sure that the early Halloween was not, as has been suggested, a holiday when druids would show up at your house and kill your sheep unless you gave them money.
We Owe the Irish and Scots for Having a Recognizable Halloween in America at All
The Protestant colonies were not exactly receptive to the idea of Halloween. The Puritans were so strict that the people of Boston actually banned the celebration of Christmas in the mid-17th century, considering it blasphemous to observe a day with the vaguest of pagan origins; obviously, a holiday that was based on spooky ghosts and divination rituals did not stand a chance. Parts of colonial America did have festivities, but they weren't widespread, and most Americans viewed Halloween as strange and foreign. Later immigrants, especially Irish immigrants fleeing the potato famine in the mid-19th century, brought over customs that were absent in the States and helped universalize a holiday that might otherwise never have truly caught on.
At One Time, Halloween Just Involved Blowing Stuff Up
There are no references to the practice of trick-or-treating as we currently recognize it in the United States before the 1930s. Instead, early accounts in America mostly focus on the mischief, which ranged from harmless (ringing doorbells and running away) to dangerous (breaking windows and setting fires). Knocking over outhouses was popular. Especially notable was the Halloween of 1913 in Sheffield, AL, when neighborhood kids planned to fill the town cannon with gunpowder and detonate it in the middle of the night. The kids were, unsurprisingly, not experts at measuring out gunpowder, and they instead set off an explosion so loud that townspeople assumed they were experiencing an earthquake. The cannon itself was thrown hundreds of feet from its foundation, and all of the windows on the hotel facing it shattered.
Jack-o-Lanterns Were Originally Carved from Turnips
The first jack-o-lanterns were fashioned from turnips and potatoes to ward off "Stingy Jack," a legendary figure who was so insufferable that he was barred from entering Heaven, but who had previously tricked the Devil into guaranteeing that he wouldn't go to Hell either. (In some versions, Jack convinces the Devil to turn into a coin so they can buy alcohol and get drunk together.) In any case, Jack wound up with nowhere to go, doomed to wander the earth, lighting his way with a burning ember inside a hollowed-out turnip—hence "Jack of the Lantern." Jack-o-lanterns in other regions were made from apples, squashes, and even cucumbers. Similarly, Germany has Rübengeister—"root vegetable ghosts"—carved from potatoes or beets.
Halloween Is Ideal for Spelling Your Future Husband's Name with Apples
Halloween and its predecessor holidays have always been considered ideal for fortune-telling and divination; Samhain was, after all, a time when the veil between the worlds of the living and the dead was at its thinnest. Naturally, the best application of this access to the realm of the dead was to ask the ghosts which boy you would marry. A woman would pare an apple, throw the skin over her shoulder, and its resulting shape would indicate the initial of her future husband's name. Or, she could approach the first man she saw on All Souls Day, and that guy's name would resemble her future husband's. Alternatively, she could just walk around a church three times and make a wish. The Irish also made barmbrack, bread that had a bunch of junk baked into it and indicated your future based on what your slice contained (a coin indicated wealth, a cloth indicated bad luck, and a ring, of course, indicated upcoming marriage, evidently the single issue that anyone cared about).