You can get married with parental or a judge consent at any age in Mississippi, New Mexico, and Oklahoma.

You can get married at 15 in Hawaii and Kansas.

You are "grandfathered" into sexual consent (not as in "marital rape" but "no longer statutory rape") when you do so.

So we may not want to be lording it too much on "international norms", particularly given that most of the marriages that happen at those ages are not "young couple got pregnant" but "older man in conservative/religious community".