The Effects That American Myths Have on Society Today

If there was not a such thing as American Cultural Myths, would America be where it is now, or better/worst? There are plenty of cultural myths floating around America; some are said to be true, and some are wished to be true. But have you ever sat back and thought about what if the American Myth of the American Dream was never a myth? Would we all still have this same dream? Or would it actually be into existence. Here is a link to a cite that lists a few American Myths. Have you heard of any of these? http://www.planetozkids.com/oban/legends.htm. Did they have an effect on the coming up of America?