Although the age of consent
is governed by statute marriage below this age is possible under certain circumstances

for example in NYC
'If either prospective bride or groom is under the age of sixteen years, in addition to parental consent, the written approval of a judge of the Supreme Court or Family Court is needed.
If you are less than 18 years of age be prepared to show proof of your date of birth. Such proof of date of birth may be one of the following: original or certified copy of birth certificate, baptismal record, passport, driver's license, naturalization record, or court records.

In all instances where either prospective bride or groom is under eighteen both parents must be present with valid identification at the time of application for the marriage license and at the marriage ceremony if the ceremony is performed in our offices. If one parent is deceased, the surviving parent must appear and a death certificate for the deceased parent must be produced. If both parents are deceased, the legal guardian must appear instead. A person under the age of fourteen cannot be married.'

HOWEVER!

......keep in mind these CHILDREN were NOT married, they did not have the legal protection of marriage, they were "spiritually married" in other words, subjected to statutory rape, turned into breeding machines, and kept as possessions with NONE of the legal right to the men's property that a legal wife would have.