Americans need a visa for China- no exempt entry.
The Chinese Visa is very easy to get at the service center
@T**
mentioned. I was given a 10 year multiple entry (even though I asked for a single). I downloaded then dropped off the completed forms on a Thursday and picked it all up the next day.
I'll note that they review your application on the spot and because of my occupation (photojournalism) I was asked to write and sign a declaration that I would not be taking and photos or videos for "work or publication". They provided a template with the wording, I did this sitting there with the agent. Weird but no problem.
China is an interesting place, it was a fun and educational trip. Enjoy!