No Congress ever has seen fit to amend the Constitution to address any issue related to marriage. No Constitutional Amendment was needed to ban polygamy or bigamy nor was a Constitutional Amendment needed to set a uniform age of majority to ban child marriages.
I was living on the wrong side of the tracks in Evanston Illinois in a home for boys. We had these Jackson 5 records. I really related to their voices - they were about my age but they were doing it.
'Dallas' hit a chord back in the late Seventies and Eighties because it was the age of greed: here you have this unapologetic character who is mean and nasty and ruthless and does it all with an evil grin. I think people related to JR back then because we all have someone we know exactly like him. Everyone in the world knows a JR.