Applicants for United States citizenship must take an in-person civics test to demonstrate their knowledge of American history and government.
During the interview, the immigration officer will ask the applicant 10 questions out of a list of 100, and the applicant must answer six correctly in order to pass the test. They must answer orally--it's not a multiple choice test!
How good is
your knowledge of civics? You can take the test
here. (Repeat tests will offer you different questions.)