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).