The American reinforcements prevented the massive German offensive in Northeastern France from sucess t or f?

Question

The American reinforcements prevented the massive German offensive in Northeastern France from sucess t or f?

Answer 1

False.  

To begin with the Americans were only in the war from 1917 so there were quite a few "massive German offensives" that they weren't there to stop.

If you mean in the period from 1917-1918 when the Americans were actually there then their contribution was important but the precise value of their assistance in any particular battle depends on the battle you are referring to.

It wasn't the American forces but the AUSTRALIAN forces in the form of the four AIF (Australian Imperial Forces) divisions which stopped the German "Operation Michael" offensive which commenced on  March 21, 1918 by an attack on Amiens. This was the principle German offensive during the time period in which American troops were present in France. American troops were dispersed to reinforce French and British forces but it was the Australians who actually stopped the attack in its tracks.

With all due respect to my fellow Americans, they do tend to exaggerate their contribution in World War I.  During the war the French lost 1,397,800 killed and 4,266,000 total casualites while the Americans lost 116,708 killed and 205,690 total casualties.

Answer 2

If you are talking about 1918 then yes, they did have a positive effect.