Conflict of laws in the United States
Conflict of laws in the United States is the field of procedural law dealing with choice of law rules when a legal action implicates the substantive laws of more than one jurisdiction and a court must determine which law is most appropriate to resolve the action. In the United States, the rules governing these matters have diverged from the traditional rules applied internationally.
Source: Wikipedia — Conflict of laws in the United States (CC BY-SA 4.0)