This is two questions and I hope my title is clear enough to communicate that. Even though the US didn't become a "superpower" until afterwards, by WW2 it seems like it had become known to the other great powers that the US and its industry were in a league above the other powers like the UK and Japan. A lot of things I've read say that the axis powers could never hope to beat the US, not to mention Yamamoto's famous "sleeping giant" quote. I've even read in some places that the US had hit that point by WW1, though I'm not sure how true that is.

The primary thing I'd like to know is at what point the US economy/industry became the "sleeping giant," Yamamoto referred to, as opposed to just another great power like France or Japan.

The second question isn't as important, since I think I already know, but when did the other great powers have a similar realization. Was there a time before WW2 that the UK realized they had been eclipsed?