what does the constitution say about how one state must regard the laws of another state?

The Constitution says that each state must generally respect the official acts, records, and judicial decisions of every other state under what is called the Full Faith and Credit Clause.

Core constitutional rule

• The rule appears in Article IV, Section 1 of the U.S. Constitution, which provides that each state shall give “full faith and credit” to the public acts (laws), records, and judicial proceedings of every other state.

• Congress is also given power to pass laws to explain how this is done and what effect those acts, records, and judgments must have when used in other states.

What “full faith and credit” means in practice

• States must recognize other states’ court judgments (for example, money judgments, child-support orders, or final divorce decrees), and those judgments usually cannot be re‑litigated from scratch in a different state.

• For “public acts” (state laws), states must respect the existence and official character of another state’s law, but they may still apply their own law instead in some situations, especially where strong local public policy is involved.

Limits and flexibility between states

• A state is not forced to enforce another state’s law if doing so would seriously violate its own fundamental public policy, even though it still acknowledges that the other law is valid in its own state.

• Courts use choice‑of‑law principles to decide when to apply their own state’s law and when to apply another state’s law, but they must do so within the framework set by the Full Faith and Credit Clause and federal statutes passed under it.

How this fits federalism

• The Full Faith and Credit Clause helps knit the states into a single national legal system so people can move, contract, and litigate across state lines without starting over legally in every new state.

• Together with the Supremacy Clause in Article VI (which makes the Constitution and federal law the “supreme Law of the Land”), it balances state autonomy with national unity in how laws and judgments operate across state borders.

Information gathered from public forums or data available on the internet and portrayed here.