In the United States a prom, short for promenade, is a formal (black tie) dance, or gathering of high school students, held at the end of senior year. While smaller schools may hold a school prom open to the entire student body, large high schools may hold two proms, a junior prom for those finishing their 11th grade year and a senior prom for those who are finishing their high school years. When the junior and senior proms are combined, it is sometimes traditional to have the junior class plan, organize, and even decorate the venue for the prom. Junior class attendees to a combined prom may still call the prom "Junior Prom". Proms are mostly attended by juniors and seniors, but some schools allow all classes to attend, usually requiring that one of the couple be an upperclassman. At some high schools, school administration may limit participation to students of the hosting school or of nearby schools. In rare cases, alumni may attend prom with students but the school may place age restrictions on such prom participants, such as requiring them to be under 21. The Junior and Senior classes may participate in fund raisers throughout the school year to reduce the prom cost.
Prom tickets are sold at school and treated as school events. Prom tickets are traditionally purchased by boys for the couple, though they may also be bought individually. It is not unusual for people attending prom as friends to purchase a "couple's ticket," as the cost of half a couple's ticket is generally less than that of one for an individual.
The name is derived from the late nineteenth century practice of a promenade ball. The end of year tradition stemmed from the graduation ball tradition.
Pre-prom activities will typically include a visit to friends' homes for group photographs.
A group of friends might rent a limousine to transport large groups to prom.
Common prom activities include (but are not limited to) dining, dancing, the crowning of a prom King and Queen, and socializing.
For high school proms in the US, some communities hold "after-prom", an activity run by parents, teachers, and community leaders for prom attendees after the formal events. Post-prom may be held at a different location from prom and might include raffles, games or a late night meal. Post-proms are organized to discourage after prom activities such as under-aged drinking and sexual activity. "Post-post prom" activities might be planned by couples such as trips to local parks or amusement parks often extending well into the next day after the prom evening.