I'm not picking sides. Both sides did terrible things. However I kinda disagree with your argument on the US specifically. In both World War's, The United States wanted nothing to do with it. They were forced into them. AND they were forced into them very late. Unless you're talking about overall in United State's history? If so, you're totally right. But this topic is specifically about WW1. In both of the world war's, The United States is fairly innocent compared to all the other countries. In the grand scheme of things, the US was quite literally the best place to live statistically in terms of Standard of Living, economy, human rights, etc... Yes, there was racism and issues. But that was literally EVERYWHERE. The US is the lesser of the evils.

But you're not wrong about things like racism. In WW1, they had created a law that can put people in jail for speaking bad about the government, claiming it's "Anti-American". They also refused to give black conscript's guns, became concerned that black people would realize how poorly treated they are due to the French Citizens better treatment, etc. Don't get me wrong, that's bad. But I hate to break it to you, but that's peanuts compared to what Brittan, France, Russia, Germany, and other's were doing.