America was great in WW2, for the UK Europe and the ROW, never underestimate that contribution. Brave boys and resources.
If Europe and the UK would have fallen who knows how that would have ended? We would have needed a bail out from Russia but they would have had a different scenario entering from the East if D day would have been repelled. A Russian loss? Disaster and a Nazi Eurasia, success? Disaster and an extended CCCP.
There are lots of other ways it was great. Europe was the center of excellence for science, look at where all the great physicists came from? The schools where they taught? Prior to 1930s?
Then the Exodus, when immigrants were welcome and the USA flourished as a result.
(It would have been awesome if that Jew, What's his face would have stayed in Manchester, a lot of bigots around at that time, we needed him)
While we were weaving black shirts and burning books, America was giving refuge to immigrants. That's pretty great.
I don't like literature that much but American art and literature is as important in the 20th century as European was in the 19th.
Cinema USA is number one.
Ok something I DO know something about. Jazz, rock and roll, Bill Hayley, Elvis (huge) Buddy Holly, Everly Bros(Brit invasion - in a nice way this time) Beach Boys, CSN, Mamas and the Papas, Hendrix, GFRR, The Doors etc etc.
That was a creative amazing two decades.
Politically?how about civil rights? Women get the vote? Ok you may not have been the first but you got there before us.
Yeah the US was AND can be great again