It is emphatically the province and duty of the Judicial Department to say what the law is.

That the people have an original right to establish, for their future government, such principles as, in their opinion, shall most conduce to their own happiness, is the basis, on which the whole American fabric has been erected.... The principles, therefore, so established, are deemed fundamental. And as the authority, from which they proceed, is supreme ... they are designed to be permanent.... The powers of the legislature are defined, and limited; and that those limits may not be mistaken, or forgotten, the constitution is written.

The particular phraseology of the Constitution of the United States confirms and strengthens the principle, supposed to be essential to all written constitutions, that a law repugnant to the Constitution is void; and that courts, as well as other departments, are bound by that instrument.

Let 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.

What are the maxims of Democracy? A strict observance of justice and public faith, and a steady adherence to virtue.

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.

In a free government almost all other rights would become worthless if the government possessed power over the private fortune of every citizen.