Is it legal for adults to marry children in the US?
Yes indeed. Varies by state, but 16 states have no minimum age requirement.
From 2000–2015, 200,000 child marriages were performed with the majority of them being girls married to adult males.
In 2001, three, ten year old girls were married to men, ranging in age from 24–31.
Yes, child marrige is alive and well in the good old USA.