59. It is not the delegation to Congress of power to regulate commerce that makes the exercise of a similar power by the State void; it is the actual exercise by Congress of its power to regulate commerce that works the prohibition. In the absence of congressional legislation on the subject the State may legislate. Thus a State law for the regulation of pilots and pilotage, in the absence of Federal law for the same, is valid.[149] This means that sovereignty acting through the State government controls—or has jurisdiction—unless sovereignty has acted in the matter through the government of the United States. Thus, where the subject, say a bridge, a wharf, or a stream, over which power may be exercised, is local in its nature and operation, or constitutes a mere aid to commerce, the authority of the State may be exerted for its regulation and management until Congress interferes and supersedes State action.[150] But a license fee exacted by a State law, from a vessel engaged in commerce is a tax for the use of navigable waters and not a charge in the nature of compensation for any specific improvement, or use of wharves. It is a burden on commerce and is a State regulation of commerce in conflict with the power of Congress to regulate it and therefore unconstitutional.[151] But the internal commerce of a State, that is, the commerce that is wholly confined within its limits is as much under its control as foreign or interstate commerce is under the control of the general government.[152] 60. By the words “taxation of commerce” is understood the taxation of the agency, means, instrument, vehicle, or article in such a way or with such effect as to control commerce; and by “control” is understood any degree of control. If the State can tax foreign or interstate commerce lightly, it can tax it heavily, and if heavily, it can so tax as to destroy commerce. So long as the article imported remains in the original form of package, the property of the importer, in his warehouse, it is within the jurisdiction of the United States; but as soon as it has become incorporated and mixed with the mass of property in the State, it is within the jurisdiction of the State and becomes subject to its taxing power.[153] Were the State to tax the importer as such, this would be a tax on importation and beyond State jurisdiction. So too would be any charges, imposed by the State, on the introduction or incorporation of the imported article into and with the mass of property in the State. The essential principle here is that the taxing power of the State cannot reach and restrain the action of the national government within its proper sphere. “It cannot interfere with any regulation of commerce.”[154]