I know there are many different and independant local sailing centers, not yacht clubs, around the country. But there are only a handfull of official "US Sailing Centers" and they offer little imediatley to any new person off the street.
I was told by US Sailing a long time ago that US Sailing really does not have anything to do with the "US Sailing Centers." They just sort of sanction them with the US Sailing name. They said they don't give them any money.
In the case of the one in Miami, the center supports itself by charging for drysail storage. And when US Sailing wants to put on a regatta there, all the dry-storage boats have to get out of there so there is room for the regatta boats.