Do Muslims in US follow the moon for Ramadan?

The majority, yes. It depends what kind of Muslim one is. If you happen to be Sunni-Muslim, then chances are your family looks throughout the moon to know when it is time to start Fasting during Ramadan. If not, then no. The moon though is to be a New Moon. If there is a New Moon in August-November, then you are to start Ramadan on whichever the New Moon is presented on.