When you were born in the US , were one or both of your parents settled there ? By settled I mean granted permanent residency or citizenship. If one or both of your parents held a green card at the time you were born, then you have no claim to Chinese citizenship. If they were say on visas , then you would be considered a Chinese citizen. I'm not too sure how it works because the US has jus soil (birthright citizenship) - anyone born on US soil has the right to US citizenship.
I was born in Canada and I tried to apply for a Hong Kong Permanent Identity Card under category 1: Chinese citizen born abroad to Chinese parents with the Right of Abode in Hong Kong and they sent me a letter outlining why I wasn't considered a Chinese citizen. My father was already a Canadian citizen at the time I was born.
If your parents were not green card holders at the time you were born , you might be able to claim Chinese citizenship on the basis that your parents were not settled abroad.