Hall et al. v. United States was a case heard by the United States Supreme Court in 1875. The case involved a dispute between the United States and the Hall family over the ownership of a parcel of land in the state of California. The Halls claimed that they had purchased the land from the Mexican government prior to the Mexican-American War, and thus had a valid title to the land. The United States argued that the land had been acquired by the United States as part of the Treaty of Guadalupe Hidalgo, and thus the Halls had no valid claim to the land. The Supreme Court ultimately sided with the United States, ruling that the Halls had no valid claim to the land. The Court held that the Treaty of Guadalupe Hidalgo had extinguished any prior claims to the land, and that the Halls had no valid title to the land. The Court also held that the Halls had failed to prove that they had purchased the land from the Mexican government prior to the Mexican-American War. As a result, the Court ruled in favor of the United States and held that the Halls had no valid claim to the land.

In Hall v. United States, the Supreme Court was asked to decide whether a federal statute that allowed for the forfeiture of property used in violation of certain customs laws applied to vessels owned by citizens of one state and seized while within another state's waters. The majority opinion held that it did apply, but Justice Field dissented on the grounds that such an interpretation would violate both Article I Section 10 Clause 2 (the "Interstate Compact Clause") and Article IV Section 2 Clause 1 ("The Privileges and Immunities Clause"). He argued that Congress had no authority under either clause to pass a law allowing for such forfeitures because they interfered with states' rights over their own internal affairs. Furthermore, he noted how this decision could have far-reaching implications if other statutes were interpreted similarly since it would allow Congress to interfere with any number of matters traditionally left up to individual states. Ultimately, Justice Field concluded his dissent by stating that although he believed there were valid reasons why Congress might want such a law on its books, those reasons should not be enough justification for violating constitutional principles which protect states from interference from outside forces like the federal government.