Invalid or prohibited marriages
Primary source
Verbatim text below is from the Electronic Code of Federal Regulations (eCFR), a public-domain U.S. government work. Always verify the current version with the eCFR before relying on it for any legal matter.
Full Text
(a) The following marriages are prohibited:
(1) A marriage entered into prior to the dissolution of an earlier marriage of one of the parties;
(2) A marriage between an ancestor and a descendant, or between a brother and a sister, whether the relationship is by the half or the whole blood;
(3) A marriage between an aunt and a nephew or between an uncle and a niece, whether the relationship is by the half or the whole blood, except as to marriages permitted by established tribal custom;
(4) A marriage prohibited by custom and usage of the tribe.
(b) Children born of a prohibited marriage are legitimate.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.