In many states, it is illegal for someone of a young age to marry even if they have parental permission. The thought is that at a young age, a person is unable to understand what marriage is and fully commit to the idea. Plus, in the past, parents may sign to consent for a marriage that is not in the best interests of their child. This leads to abuse and other criminal situations within the marriage. In Alabama, the law still allows for children to marry in many cases.
According to AL.com, the law does require both parents to consent and an approval from a judge if the child is under the age of 16. Some states have a pregnancy exception that allows marriage if a girl is pregnant, but Alabama law does not. The law saw some strengthening in 2003, which helped to reduce the number of child marriages in the state.
However, the legal age to marry is still a child. Age 16 is a long way away from age 18, which marks the official independence of adulthood. Many fear that parents force young girls into marriages at young ages, which does not give girls ages 16 and 17 the ability to object. Furthermore, if there is abuse in the situation, the law stands with the parents because running away is not an option. Law enforcement would have to return you to your parents who would then take you back to your spouse.
Overall, the concern is that child marriage gives power to everyone but the child. Fortunately, the number of child marriages in the state is dropping. This information is for education and is not legal advice.