Personally, I look upon the U.S the way any proud parent would at their enormous, occasionally wayward but hugely promising child. I suspect great things from this particular descendant for the greater community of the earth, once its overinflated sense of self importance is checked somewhat and a more respectful and considerate attitude is adopted towards other, longer established, and worthwhile cultures. As for its positive contribution to the global pot up to now, I would say ‘awesome’ :- Rock & Roll, Jazz, Country, Hollywood (The good stuff), Breathtaking automobile designs, the streamlining of the language, Denim, Skyscrapers, Great tv (Addams Family, Beverley Hillbillies, The Munsters, Sgt. Bilko, Roots, Starsky and Hutch, Hill Street Blues, Lost, The Sarah Connors Chronicles) to name but a few.
On the whole, you’re doing good kid. :-)