Why are school 'Formals' (Australia) or 'Balls' (U.K.) called 'Proms' in the U.S.A.? Where does the word 'prom' come from?

The word 'promenade' is defined either as a leisurely walk or a place for walking> It is also used to represent movements in ballet and ballroom dancing. In the US in the late 19th century, it gained an additional meaning when "promenade concerts" were held at Ivy League colleges, where attendees would dance in formal attire. It is unclear when 'promenade' was shortened to 'prom', but an article from the December 5, 1879, issue of "The Harvard Crimson" referenced the "Junior Prom." In 1895, a diary entry from Dwight Morrow (who later became a US senator) stated that he had been invited to a junior prom at Smith College. In his records, he had a photo showing a junior prom held at the school's Gymnasium. After this time, the popularity of the dances spread rapidly to high schools. In "Prom Night: Youth, Schools and Popular Culture", author Amy Best described "a democratized version of the debutante ball." She stated that "The prom allowed anyone attending high school to feel as though they too were 'coming out,' that they could transcend the boundaries of class... The message was that you did not have to be rich to wear a fancy frock, to be adorned with a corsage, or to waltz the night away." Proms took off in popularity in the 1930s. According to Ann Anderson in her work "High School Prom: Marketing, Morals and the American Teen," the 1940s marked the emergence of teenagers as a distinct consumer demographic and were recognised as the "golden age of prom." During this period, dances began moving from school gyms to luxury hotels, with the crowning of prom kings and queens became a common part of proceedings.

https://www.history.com/articles/prom-invention-traditions
https://www.usatoday.com/story/life/2023/05/10/evolution-of-american-proms-history/70180370007/