Pennock v. Commissioners is a United States Supreme Court case that was decided in 1881. The case involved a dispute between the Pennock family and the Commissioners of the City of Philadelphia. The Pennock family owned a large tract of land in Philadelphia, and the Commissioners had attempted to take the land for public use without providing the Pennock family with just compensation. The Pennock family argued that the taking of their land was unconstitutional, as it violated the Fifth Amendment of the United States Constitution, which states that private property shall not be taken for public use without just compensation. The Supreme Court agreed with the Pennock family, ruling that the taking of their land was unconstitutional. The Court held that the Fifth Amendment requires that the government provide just compensation when it takes private property for public use. The Court's decision in Pennock v. Commissioners established an important precedent in the area of eminent domain law. The decision established that the government must provide just compensation when it takes private property for public use, and it has been cited in numerous subsequent cases involving the taking of private property.

Pennock v. Commissioners was a case heard by the United States Supreme Court in 1881, which dealt with the issue of whether or not a state could tax federal property within its borders. The majority opinion held that states had no authority to impose taxes on federal property, as it would be an unconstitutional infringement upon Congress’s power to make all laws necessary and proper for carrying out their enumerated powers. However, Justice Field dissented from this ruling and argued that while Congress has exclusive control over certain matters related to national government operations, taxation is not one of them; instead he believed that taxation should remain under the jurisdiction of individual states. He further reasoned that if Congress were allowed to have exclusive control over taxing federal property then they would essentially be able to exercise unlimited power over any matter relating thereto - something which he felt was contrary both to constitutional principles and public policy considerations. Ultimately his dissent did not sway the court's decision but it remains an important reminder of how different interpretations can lead two sides in opposite directions when interpreting complex legal issues such as those presented in Pennock v Commissioners