State inspection laws, health laws, and laws for regulating the internal commerce of a State, and those which respect turnpike roads, ferries, &c. are not within the power granted to Congress. ... Inspection laws, quarantine laws, health laws of every description, as well as laws for regulating the internal commerce of a State, and those which respect turnpike roads, ferries, &c., are component parts of this mass. No direct general power over these objects is granted to Congress, and, consequently, they remain subject to State legislation.
John MarshallAn unlimited power to tax involves, necessarily, a power to destroy; because there is a limit beyond which no institution and no property can bear taxation.
John MarshallLet the end be legitimate, let it be within the scope of the constitution, and all means which are appropriate, which are plainly adapted to that end, which are not prohibited, but consist with the letter and spirit of the constitution, are constitutional.
John MarshallWhat is it that makes us trust our judges? Their independence in office and manner of appointment.
John Marshall