Freedom of movement under United States law

Freedom of movement under United States law is governed primarily by the Privileges and Immunities Clause of the United States Constitution which states, "The Citizens of each State shall be entitled to all Privileges and Immunities of Citizens in the several States." As far back as the circuit court ruling in Corfield v. Coryell, 6 Fed. Cas. 546 (1823), the Supreme Court recognized freedom of movement as a fundamental Constitutional right. In Paul v. Virginia, 75 U.S. 168 (1869), the Court defined freedom of movement as "right of free ingress into other States, and egress from them." However, the Supreme Court did not invest the federal government with the authority to protect freedom of movement. Under the "privileges and immunities" clause, this authority was given to the states, a position the Court held consistently through the years in cases such as Ward v. Maryland, 79 U.S. 418 (1871), the Slaughter-House Cases, 83 U.S. 36 (1873) and United States v. Harris, 106 U.S. 629 (1883).

As early as the Articles of Confederation the Congress recognized freedom of movement (Article 4), though the right was thought to be so fundamental during the drafting of the Constitution as not needing explicit enumeration.

The U.S. Supreme Court in Crandall v. Nevada, 73 U.S. 35 (1868) declared that freedom of movement is a fundamental right and therefore a state cannot inhibit people from leaving the state by taxing them. In United States v. Wheeler, 254 U.S. 281 (1920), the Supreme Court reiterated its position that the Constitution did not grant the federal government the power to protect freedom of movement. However, Wheeler had a significant impact in other ways. For many years, the roots of the Constitution's "privileges and immunities" clause had only vaguely been determined. In 1823, the circuit court in Corfield had provided a list of the rights (some fundamental, some not) which the clause could cover. The Wheeler court dramatically changed this. It was the first to locate the right to travel in the privileges and immunities clause, providing the right with a specific guarantee of constitutional protection. By reasoning that the clause derived from Article IV of the Articles of Confederation, the decision suggested a narrower set of rights than those enumerated in Corfield, but also more clearly defined those rights as absolutely fundamental.

...
Wikipedia