there is a "Naturalization Test for Immigrants" in USA similar to one in Germany. You can test yourself here:
At the moment I can not compare the both tests (Germany vs. USA) as my german is not good enaugh. Maybe you could compare them for me. I think the german-test ist easier.
The links does not work. Here is another one: http://www.uscis.gov/citizenship/teachers/educational-products
Example question (number 81) :
Q: Who did the United States fight in World War II?
A: Japan, Germany, and Italy