Chief Justice John Marshall (on navigation as a form of commerce): “If commerce does not include navigation, the government of the Union has no direct power over that subject, and can make no law prescribing what shall constitute American vessels, or requiring that they shall be navigated by American seamen. Yet this power has been exercised from the commencement of the government, has been exercised with the consent of all, and has been understood by all to be a commercial regulation. All America understands, and has uniformly understood, the word ‘commerce,’ to comprehend navigation. It was so understood, and must have been so understood, when the constitution was framed. The power over commerce, including navigation, was one of the primary objects for which the people of America adopted their government, and must have been contemplated in forming it. The convention must have used the word in that sense, because all have understood it in that sense; and the attempt to restrict it comes too late.”

Marshall (on the broad scope of Congress’s commerce powers): “We are now arrived at the inquiry—What is this power? It is the power to regulate; that is, to prescribe the rule by which commerce is to be governed. This power, like all others vested in Congress, is complete in itself, may be exercised to its utmost extent, and acknowledges no limitations, other than are prescribed in the constitution. These are expressed in plain terms, and do not affect the questions which arise in this case, or which have been discussed at the bar. If, as has always been understood, the sovereignty of Congress, though limited to specified objects, is plenary as to those objects, the power over commerce with foreign nations, and among the several States, is vested in Congress as absolutely as it would be in a single government, having in its constitution the same restrictions on the exercise of the power as are found in the constitution of the United States. The wisdom and the discretion of Congress, their identity with the people, and the influence which their constituents possess at elections, are, in this, as in many other instances, as that, for example, of declaring war, the sole restraints on which they have relied, to secure them from its abuse. They are the restraints on which the people must often they solely, in all representative governments.

“The power of Congress, then, comprehends navigation, within the limits of every State in the Union; so far as that navigation may be, in any manner, connected with ‘commerce with foreign nations, or among the several States, or with the Indian tribes.’ It may, of consequence, pass the jurisdictional line of New York, and act upon the very waters to which the prohibition now under consideration applies.”