Trick-or-treating resembles the medieval practice of souling, where poor folk would go from door to door on Hallowmas (November 1st) carrying their ‘Jack o’ lanterns’ to receive food in exchange for prayers for the dead on All Souls Day (November 2nd) It is believed to have originated in Ireland and Britain.
The trick usually involves a veiled, generally idle, threat to trash the garden, the house or perform some mischievous prank or other on the homeowner while a treat would consist of sweets, or in some cultures, money!
Halloween costumes are traditionally modelled on supernatural figures, monsters, ghosts, skeletons, witches, and devils, while more recently this has extended to include popular characters from fiction, celebrities, and generic archetypes such as ninjas and princesses. Dressing up in costumes and going “guising” was prevalent in Ireland and Scotland at Halloween by the late 19th century.
Costuming became popular for Halloween parties in the US in the early 20th century, as often for adults as for children. The first mass-produced Halloween costumes appeared in stores in the 1930’s when trick-or-treating was becoming popular in the United States.