In the early Sixties GM was explicitly out of the excitement business. Racing was banned and the various divisions were supposed to fall in line and produce sensible machinery. But at Pontiac the young chief enginer John Z. Delorean had the bright idea of shoving the company's 389-cubic inch V8 into the mid-size Tempest to create the GTO. Throw in a couple of fake hood scoops, some strategically placed trim and the result was the first car that everyone recognized as a muscle car.
Why it's uniquely American: Simple car, big engine and a name stolen from Ferrari.