This is, of course, a matter of personal opinion. I will provide an argument for each side of the question and you can decide what your view is.
We can argue that the US should have entered the war for a variety of reasons. First, there was the illegal and indiscriminate submarine warfare practiced by the Germans. This was against international law at the time. It was also inhumane because the Germans were sinking ships that had innocent passengers on them, leading to the deaths of people who were not part of the war. Second, there was the fact that Germany aggressively invaded Belgium and France. Germany had no need to do either of those things. Since Germany struck first, without being invaded, they were in the wrong. Third, the Allied powers were democracies while the Central Powers were not. By the time the US entered the war, the other Allied powers were France and England, both of which were democratic. It was good for the US to fight for democracy and against the monarchies of Germany and Austria. Finally, it was in the US’s economic and social interests to help the Allies. We had much more trade with England than with any of the Central Powers. We had historical ties with England. In short, England was really an ally of ours (even if we had no official treaties) so it was right for us to side with them.
On the other hand, we can argue against American participation in this war. First, we can say that the war had nothing to do with the US. The fight was going on in Europe where it could not hurt us. We should have just stayed out of it. Second, we can argue that the British were breaking international law too. They were not using submarines, but they were illegally preventing neutral countries like the US from trading with Germany and the other Central Powers. We can say it was wrong to punish Germany for breaking international law when England was doing the same thing. Third, we can argue that the war was not about democracy. The Allies were not trying to spread democracy and the Central Powers were not trying to destroy it. The war was really just a struggle for power between two sets of countries, not between two ideologies. Fourth, we can say that many Americans did not want to side with England. There were many Americans of German or Irish descent who would have preferred that we stay out of the war. Finally, we can say that it is wrong to fight a war for financial reasons. The fact that we traded with England a lot should not have been a reason to actually enter the war on their side. Wars are supposed to be about right and wrong, not about money and power.
Which of these arguments makes more sense to you?