“Most unquestionably there is no legal tender, and there can be no legal tender, in this country, under the authority of this government or any other, but gold and silver, either the coinage of our own mints, or foreign coins, at rates regulated by Congress. This is a constitutional principle, perfectly plain, and of the highest importance. The states are expressly prohibited from making anything but gold and silver a tender in payment of debts; and although no such express prohibition is applied to congress, yet as congress has no power granted to it, in this respect, but to coin money and to regulate the value of foreign coins, it clearly has no power to substitute paper, or anything else, for coin, as a tender in payment of debts and discharge of contracts… The legal tender, therefore, the constitutional standard of value, is established and cannot be overthrown. To overthrow it, would shake the whole system. The constitutional tender is the thing to be preserved, and it ought to be preserved sacredly, under all circumstances.
– Daniel Webster, in a speech before the Senate on December 21, 1836

 

From A plea for the Constitution of the U.S. of America: wounded in the house of its Guardians by George Bancroft, pp. 93-94

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