Before revision: Flappers were a subculture of young Western women in the 1920s who wore short skirts (knee height was considered short during that period), bobbed their hair, listened to jazz, and flaunted their disdain for what was then considered acceptable behavior.
After revision: Flappers were a subculture of young Western women prominent after the First World War and through the 1920s who wore short skirts (knee height was considered short during that period), bobbed their hair, listened to jazz, and flaunted their disdain for prevailing codes of decent behavior.