Would that have been an acceptable solution for interracial marriage? Alabama doesn't have to allow it, but if an already married couple moves to Alabama they get to stay married? Meanwhile their neighbors, who also happen to be an interracial couple, can't get married without first traveling to some other state that recognizes it?
Just stop joe. You're an idiot.
Age of consent to marry varies from State to State. When Harry, who is 21, legally marries 15 year old Sally in the State of Hawaii and then moves to Jersey City, he's still legally married, despite what the State of New Jersey may think about it.
If he met Sally in Atlantic City, he'd have to wait until she's 16 if he can get parental consent or 18 if not.