Not to sound too incendiary, but the first "American" to space was actually born in Cameroon. Prior to sending up men to orbit around the Earth, we sent Ham the chimpanzee. He pushed a button. What he accomplished isn't significantly less than the scientific progress gained on the International Space Station, with the exception of knowledge of the long term effects of micro-gravity on humans.
At present time, human space exploration is a matter of putting the cart before the horse. I agree with Ichy above that the space station is mostly purposeless. (With the exception noted above - study of effects on humans.)
But, I disagree with the comment that the space program has been withering. Look at our sudden rapid discovery of exo-planets. We've sent a flyby craft with a probe to impact a comet (comet Tuttle 1, deep impact probe), the little Rovers on Mars, studies of Jupiter and it's moons, as well as Saturn and its moons and rings, etc. Not to mention a lot of the data collected about our own planet. The most significant science and learning has occurred without manned space flight. We sent men to the moon - it had one major accomplishment: we beat the Russians to the moon. For the cost of another manned mission to the moon, we could instead be learning even more about many of the moons in our solar system, and probing the liquid water oceans that exist on a few of them. Is there other life out there?