Blame the Japanese. The US was not a powerhouse prior to WWII, and even tried to stay out of the war. Once Pearl Harbor happened, the US went into a** kicking mode and has never looked back.
History lesson time.
That's not true at all. The US was an
industrial powerhouse. We didn't build all that in the weeks after Pearl Harbour. It was already there. We just mobilized. Very, very different from "not being a powerhouse".
Even then you're still wrong. It wasn't the Confederate flag flying over Government property all the way up the 1950s when black folks were enduring segregation.
It wasn't the Confederate flag flying over a nation that committed physical & cultural genocide against the First Nations and discriminated against them by preventing First Nations folk from a) practising their cultural belief systems b) being recognised as U.S. citizens up until the 1960s.
The Star-Spangled Banner is a symbol of racism to some as much as the Swastika or the Rising Sun.
eh.
The Stars & Stripes are over 200 years old. It stands for the American state and people as a whole, rather than something like the NSDAP flag, which was constructed to symbolize Aryan-German supremacy. You could argue that the Union Jack is just as racist using this logic, but
it isn't because it represents more than one particular era of the British government.
I'd go so far as to say that even the Rising Sun could be seen the same way, because it is
not a state flag in the traditional sense of the term but one that symbolizes/symbolized the Japanese armed forces from the Meji Restoration onward.
The American, British and so on flag have pedigrees far larger than something like the NSDAP banner. It's just as stupid as when people claim the Schwarz-Weiß-Rot is a symbol of Nazis and hate. No, it doesn't. It predates them by quite a bit and means something
very different.