Article IV: Relations Among the States & Federal Government

The Clause promotes interstate legal continuity by preventing states from simply disregarding qualifying official acts and court judgments of other states.

Public acts include qualifying state laws and governmental acts. The constitutional requirement does not mean that every law enacted by one state automatically governs conduct occurring in another state. Conflict-of-laws principles, constitutional provisions, and Supreme Court doctrine determine when another state must recognize or give effect to a particular law or legal status.

Official records of one state are subject to interstate recognition under the Clause. Congress has authority to prescribe procedures for authenticating such records and determining their evidentiary or legal effect.

Final judicial proceedings can receive recognition and effect in other states. This principle helps prevent parties from relitigating matters that have already been conclusively adjudicated in another state, subject to applicable constitutional and procedural rules.

The Clause has traditionally operated particularly strongly with respect to final judgments. Recognition of another state’s judgment is different from a general command that one state must apply another state’s substantive laws to all conduct occurring within its borders.

Congress may establish general rules governing the authentication and effect of state acts, records, and judicial proceedings. Congress has exercised this authority through federal legislation governing recognition of state records and judgments.

Full Faith and Credit supports mobility and legal stability in a nation where people, businesses, property, and legal relationships regularly cross state boundaries.

Citizens of each state are entitled to the privileges and immunities of citizens in the several states. The Clause generally prevents a state from discriminating against citizens of other states with respect to fundamental rights or important activities when the discrimination lacks sufficient justification.

The Privileges and Immunities Clause does not require states to make every law identical for residents and nonresidents. States may make some distinctions between residents and nonresidents when constitutional doctrine permits those distinctions, particularly where the distinction concerns matters that are not protected privileges or immunities under the Clause.

Supreme Court doctrine has treated certain fundamental activities and rights, including pursuing a common calling, access to courts, and earning a livelihood in appropriate circumstances, as potentially protected against discriminatory treatment of out-of-state citizens. The Clause’s precise scope is determined through judicial precedent.

The Article IV Privileges and Immunities Clause is distinct from the Fourteenth Amendment’s Privileges or Immunities Clause. Article IV concerns discrimination by one state against citizens of another state, while the Fourteenth Amendment restricts state interference with the privileges or immunities of U.S. citizens and also contains separate Due Process and Equal Protection guarantees.

A person charged in one state with treason, felony, or another crime who flees from justice and is found in another state is constitutionally subject, on demand of the executive authority of the state from which the person fled, to be delivered up and returned to the state having jurisdiction of the crime.

Interstate extradition prevents a person from escaping prosecution simply by crossing a state border. It reflects the principle that criminal jurisdiction generally remains with the state in which the alleged offense occurred.

The constitutional extradition obligation operates alongside federal law and state procedures governing the formal requisition, certification, arrest, and transfer of a person sought by another state.

The third paragraph of Section 2 originally required the return of persons held to service or labor who escaped to another state. That provision was part of the constitutional protection of slavery and is no longer operative.

The Thirteenth Amendment abolished slavery and involuntary servitude, except as punishment for a crime after due conviction. The constitutional change therefore superseded the fugitive-slave provision in Article IV, Section 2.

Congress may admit new states into the Union. Admission is a congressional power rather than an automatic process triggered merely by the population or geographic development of a territory.

A new state may not be formed within the jurisdiction of an existing state without the required consent of the affected state legislature and Congress.

No state may be formed by joining two or more existing states, or parts of states, without the consent of the legislatures of the states concerned as well as Congress.

Congress normally establishes the legal process and conditions for state admission. Once admitted, a new state enters the Union on a constitutional footing governed by the Constitution and applicable federal law.

The second paragraph gives Congress power to dispose of and make all needful rules and regulations respecting territory or other property belonging to the United States. This is commonly known as the Territorial Clause or Property Clause.

The Territorial Clause provides an important constitutional basis for congressional governance of U.S. territories. Territories are not automatically states and may operate under legal arrangements established by Congress consistent with the Constitution.

Congress also has authority concerning other property belonging to the United States. The provision covers federal lands and other forms of federal property, subject to other constitutional provisions.

Section 3 states that nothing in the Constitution shall be construed to prejudice claims of the United States or of a particular state concerning territory or property.

The United States guarantees each state a republican form of government. The provision reflects the constitutional expectation that states operate through representative constitutional governments rather than hereditary monarchies.

The Republican Form of Government provision is commonly called the Guarantee Clause. Its interpretation has raised important questions about the role of federal courts in reviewing claims involving the political structure of state government.

The federal government has a constitutional responsibility to protect each state against invasion. This provision reflects the national government’s role in defending the Union and its member states.

The United States may be called upon to protect a state against domestic violence when the state legislature applies for federal assistance, or when the legislature cannot be convened and the application comes from the state executive. This constitutional provision forms part of the framework for federal assistance during severe internal disturbances.

Section 4 does not erase state authority over ordinary law enforcement. Instead, it establishes circumstances in which the federal government has constitutional responsibilities toward a state facing specified threats.