Wernher von Braun was lead constructor/technologist for the Apollo missions, and provided his knowledge about rocket science, which he used/learned during WW2 when constructing the V2 (along with some other german rocket-scientist which emigrated also to the United States and worked on projects there after WW2). So, this is maybe a hypothetical question, but would the Americans have been able to reach the moon without him or the other German scientists? (And if so, would it have been at 1969 or years later?)
How important was his role, and how good was the american knowledge about advanced rocket science without including the knowledge they gained from the germans after winning WW2? I have never heard about advanced american rocket-technology before von Braun emigrated there, did they even engage with this topic before 1945?
Wikipedia only states that he had the leadership in several projects including the Apollo Mission and the Saturn V rocket.
Edit: i changed question. They could have reached the moon anyway, but more interesting is, if they had a chance to beat russia without the third reich technology. I guess america would have done the same as russia did when they lost the race. Stop the program because it was to expensive and they already had lost.
Also removed the word Nazi, because this lead to discussions which are not on topic of the question.