I may be mistaken about this, but I don't think marriage is a federal issue. I think it is a state issue. If RXSID is correct about this, Hawaii may have had no law against it. Is there a Federal law against polygamy? And if so, what is it's basis in Constitutional authorization?
Upthread the federal law was posted. Remember that Utah wasn’t allowed to become a state until it agreed to pass an anti-plural marriage law meeting federal requirements.
I’m sorry, I meant United States in the sense “the States” rather than as a national description.