How did World War I affect American society after the war?How did World War I affect American society after the war?
Nobody referred to this conflict as "World War I" at the time, as they had no idea there was a World War II on the horizon. As it dragged on year after year, and the death toll ran into the millions, it became known as "The Great War", and "The War to End All Wars".
This gives you a hint of how Americans and others were affected by this war. For some, such as Woodrow Wilson and much of the public, it gave rise to an entire movement to end war forever, to look for what causes war (such as who controls the oceans) and address those questions, hopefully permanently. This was the purpose of Wilson's Fourteen Points.
Others were gripped with a sense of hopelessness, that mankind was doomed to destroy itself, somehow, some day. Therefore, we should "live for today", or "live in the moment". The 20s in America were social "roaring" too, that is, many in society thoroughly enjoyed themselves, whether it was through drinking during prohibition, dancing in all night clubs, or experimenting with social values on sex and love.
World War I was the first technological war. It wiped out almost an entire generation of young able-bodied men. It was a deadly war. Soliders did come back alive, but horribly disfigured and with post-traumatic stress. When they did return, they had difficulty finding their way back into the social structure.