'I consider the foundation of the Constitution as laid on this ground: That "all powers not delegated to the United States, by the Constitution, nor prohibited by it to the States, are reserved to the States or to the people." To take a single step beyond the boundaries thus specially drawn around the powers of Congress, is to take possession of a boundless field of power, no longer susceptible of any definition.'(Emphasis added to Jefferson quote by Double Birds)
Jefferson quote source: Opinion on the Constitutionality of the National Bank