chapotraphouse

Its actually most of the US: https://en.m.wikipedia.org/wiki/Child_marriage_in_the_United_States

Although that's with all the exceptions on the book. It might be easier to get the exceptions in the bible belt.

Also notable: states with zero minimum age using all exceptions CA, OK, NM, MS.

Edit: in 2017 there were 25 states with no minimum age. All 13 states with 18 as the final minimum were applied after 2018. The triggering event seems to be HRW pointing out Afghanistan had better child marriage laws than the US. So this is something that the US is just now coming to terms with.