WWII was the last time the US "won" a war, so it gets more attention.

Damn, you're right. WW1 was certainly a major international conflict. Scratch that bit.

It does offer a useful comparison though. In WW1 there were no cartoonishly evil baddies, just a bunch of pointless deaths. It didn't devastate a civilian population, either - nobody got to feel like a hero, there were no joyful liberations. WW2 was a righteous war (that also happened to be an economic goldmine). That permanently shifted American culture (and killed isolationism stone dead). So Nazis became THE enemy - the Lucifer to America's new God complex.

The Germans were cast as, if anything, even more evil characters in the WW1-era propaganda than they were in WW2. A series of atrocities in the opening phase of the war while the German armies were marching through Belgium were widely reported and inflated into stories of raping nuns and bayonetting babies.

In contrast, the full scale of the horrors of the Nazi regime were not widely known until the final days of WW2.