The clause helps a federal union function across state borders. A creditor who obtained a valid final judgment should not ordinarily have to relitigate the merits after the debtor moves. That obligation differs from requiring every state to copy another state's regulatory code for conduct occurring within its own territory.

Check what crosses the border: a judgment, official record, or statute. Then ask whether the first court had jurisdiction and whether the second state is recognizing an adjudicated obligation or selecting law for a new controversy. The clause promotes interstate respect without eliminating distinct state legal systems.

A test item involving enforcement of a sister-state court judgment points most directly to full faith and credit. A dispute about discrimination against visiting citizens instead invokes Article IV privileges and immunities, while conflict with a federal statute raises supremacy and preemption.

Video lesson: Federalism: Crash Course Government and Politics #4