AP US History has become a purely cultural Marxist exercise in deconstruction.
The exam (which you have to get a 4 or 5 on to claim the credit) is like a Chinese Cultural Revolution exercise in self-criticism. If your kid is uncomfortable denouncing his own people and his own country, he should stay away.
About 5 years ago, only about 40% passed the test. Not worth stressing your kid out for it.