Without Americans, people would still be riding around in buggies, because there would be no vehicles. Forget about trans-Atlantic or Pacific flights; there'd be no airplanes. The world would be overrun with even more diseases, because there wouldn't be American scientists to discover cures.
No need for many electrical devices, motion pictures, phonographs or telephones, because Thomas Edison and Alexander Graham Bell (though born in Scotland) wouldn't be around. Computers, the Internet - what are those? No one would know because they wouldn't exist without Americans.
There would be no Robert Fulton (the steamboat); Samuel F.B. Morse (the telegraph); Eli Whitney (the cotton gin); Willis Haviland Carrier (air conditioning); George Eastman (portable cameras, photographic film); Elisha Graves Otis (elevators); Clarence Birdseye (frozen foods); Les Paul (electric guitar); Henry W. Seely (electric iron).
Without Americans, there'd be no jeans, jukeboxes, MRIs, microwave ovens, nuclear reactors, refrigerators, respirators, satellite communications, Scotch tape, skateboards, skyscrapers, staplers, Teflon, toilet paper, tractors, traffic lights, transistors, typewriters, videotape, electric washing machines, zippers.
Around 40% (almost half) of the world's RISKY R&D spending is done -- by the US, and US private firms.
Without the U.S., there is little to no technological progress.
China reverse-engineers all our commercial developments; Canada and other free-rider countries get our pharm. innovations (new drugs) - at a cut rate...
The US is great because we REWARD risk taking, and live-giving technologies and innovations. THESE THINGS ARE COSTLY, but help the world permanently/for generations.
Nobody wants to pay for them; WE pay for them, and encourage their development via profit incentive....
Duh! Is this HaRd?? NO.
Go USA!!!