I shall contend that the power of Congress to regulate commerce is complete and entire, and, to a certain extent, necessarily exclusive; that the acts in question are regulations of commerce, in a most important particular, affecting it in those respects in which it is under the exclusive authority of Congress.  I state this first proposition guardedly.  I do not mean to say, that all regulations which may, in their operation, affect commerce, are exclusively in the power of Congress; but that such power as has been exercised in this case does not remain with the States.  Nothing is more complex than commerce; and in such an age as this, no words embrace a wider field than commercial regulation.  Almost all the business and intercourse of life may be connected incidentally, more or less, with commercial regulations.  But it is only necessary to apply to this part of the Constitution the well-settled rules of construction.  Some powers are held to be exclusive in Congress, from the use of exclusive words in the grant; others, from the prohibitions on the States to exercise similar powers; and others, again, from the nature of the powers themselves.  It has been by this mode of reasoning that the court has adjudicated many important questions; and the same mode is proper here.  And, as some powers have been held to be exclusive, and others not so, under the same form of expression, from the nature of the different powers respectively; so where the power, on any one subject, is given in general words, like the power to regulate commerce, the true method of construction will be to consider of what parts the grant is composed, and which of those, from the nature of the thing, ought to be considered exclusive.  The right set up in this case, under the laws of New York, is a monopoly.  Now I think it very reasonable to say, that the Constitution never intended to leave with the States the power of granting monopolies either of trade or of navigation; and therefore, that, as to this, the commercial power is exclusive in Congress.

It is in vain to look for a precise and exact definition of the powers of Congress on several subjects.  The Constitution does not undertake the task of making such exact definitions.  In conferring powers, it proceeds by the way of enumeration, stating the powers conferred, one after another, in few words and where the power is general or complex in its nature, the extent of the grant must necessarily be judged of, and limited, by its object, and by the nature of the power.

Few things are better known than the immediate causes which led to the adoption of the present Constitution; and there is nothing, as I think, clearer, than that the prevailing motive was to regulate commerce; to rescue it from the embarrassing and destructive consequences resulting from the legislation of so many different States, and to place it under the protection of a uniform law.  The great objects were commerce