Just started reading The Great Influenza by John Barry. As we have been reminded, the "Spanish Flu" occurred in 1918 which devastated the country after WWI. Made me wonder if the Roaring 20's was largely caused with the "celebration of life" from those that survived the flu.
The flu was tragic civilian icing, but the WAR was the cake that served the ending of the Machine Age for Europe and for America... all the optimism, expansion, modern culture advances, progressive policy embodied in Edison, Bell, the Wright brothers, Sinclair, TR and the 1893 exhibition was hollowed out when all saw witnessed the indiscriminate killing/maiming machine of war could do.
Add to it...Prohibition, and you had then what have what we have now.. of course, we might be nearer the end of the 1920s... market crashes, economy shattering, lots of wealth at the top...corrupt business practice...and speculators everywhere... so the Golden Age part 2 might be ending, rather than primed.