(mc) what effect did the entry of the united states into world war 1 have on the course of the war?

 It helped bring a quick victory to the Allies.

The United States had been providing some support to the Allies prior to its own entry into the war.  But when the US joined the effort fully with a declaration of war, that not only meant the arrival of fresh US troops but a commitment of even more American dollars to the Allies' war effort.  The American commitment greatly boosted the morale of British and French troops on the Western front and demoralized the German troops.

If you're looking at a question with other multiple choice answers, here are problems with some other answers I've seen listed with this question.

i don't see how you want other people to do your work for you and it is like you are just handing your assignment to anybody else and having them deal with it instead of your self i thought this site was for asking questions and somebody could you on it not just handing your work to somebody else to deal with it just saying don't mean to be mean just proving a fact.

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