U.S. ratification of the Convention on the Rights of the Child
The United States has signed the United Nations Convention on the Rights of the Child (UNCRC); however, it remains the only United Nations member state to have not ratified it after Somalia ratified it in 2015. U.S. non-ratification of this document results in children having no standing in court.
Source: Wikipedia — U.S. ratification of the Convention on the Rights of the Child (CC BY-SA 4.0)