How did youth culture change during the 1920s?

            Following the destruction caused by World War I, it became obvious that the United States needed to rebuild itself. Many long-held pre-war values and customs seemed irrelevant now, perhaps more so than ever before. Because of this, the youth of America began rebelling against many of the norms of their parents' generation as they strove to create something uniquely their own. Eventually, this new youth culture of the 1920s became the focus of a national obsession. Even adults played a part, with some attempting to imitate the new trends while others found themselves repulsed by them. But whatever adults of the time felt, they could not deny that the new world created by their country's youth was having a drastic effect on the American population as a whole. Though the defining characteristics of the movement may appear now to be fairly simple to pin down, the youth culture of the 1920s had synthesized new ideas of the post-war era with America's older traditions in such a way that a complex movement was created, reinvigorating the overall American population.

Answer is mass marketing.