Halloween Girls Kissing

Dressing up in costumes and going "guising" was prevalent in 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 1930s when trick-or-treating was becoming popular in the United States.
Halloween costume parties generally fall on, or around, 31 October, often falling on the Friday or Saturday prior to Halloween.
• UNICEF
"Trick-or-Treat for UNICEF" has become a common sight during Halloween in North America. Started as a local event in a Northeast Philadelphia neighborhood in 1950 and expanded nationally in 1952, the program involves the distribution of small boxes by schools (or in modern times, corporate sponsors like Hallmark, at their licensed stores) to trick-or-treaters, in which they can solicit small-change donations from the houses they visit. It is estimated that children have collected more than $118 million for UNICEF since its inception. In Canada, in 2006, UNICEF decided to discontinue their Halloween collection boxes, citing safety and administrative concerns; after consultation with schools, they instead redesigned the program.