It is believed that not one example can be given, from the first settlement of our country to the adoption of this Constitution, of a post-office being established without a view to existing roads or of a single road having been made by pavement, turnpike, etc., for the sole purpose of accommodating a post-office.  Such, too, is the uniform progress of all societies.  In granting, then, this power to the United States it was undoubtedly intended by the framers and ratifiers of the Constitution to convey it in the sense and extent only in which it had been understood and exercised by the previous authorities of the country.

This conclusion is confirmed by the object of the grant and the manner of its execution.  The object is the transportation of the mail throughout the United States, which may be done on horseback, and was so done until lately, since the establishment of stages.  Between the great towns and in other places where the population is dense stages are preferred because they afford an additional opportunity to make a profit from passengers; but where the population is sparse and on crossroads it is generally carried on horseback.  Unconnected with passengers and other objects, it can not be doubted that the mail itself may be carried in every part of our Union with nearly as much economy and greater dispatch on horseback than in a stage, and in many parts with much greater.  In every part of the Union in which stages can be preferred the roads are sufficiently good provided those which serve for every other purpose will accommodate them.  In every other part where horses alone are used if other people pass them on horseback surely the mail carrier can.  For an object so simple and so easy in its execution it would doubtless excite surprise if it should be thought proper to appoint commissioners to lay off the country on a great scheme of improvement, with the power to shorten distances, reduce heights, level mountains, and pave surfaces.

If the United States possessed the power contended for under this grant, might they not in adopting the roads of the individual States for the carriage of the mail, as has been done, assume jurisdiction over them and preclude a right to interfere with or alter them?  Might they not establish turnpikes and exercise all the other acts of sovereignty above stated over such roads necessary to protect them from injury and defray the expense of repairing them?  Surely if the right exists these consequences necessarily followed as soon as the road was established.  The absurdity of such a pretension must be apparent to all who examine it.  In this way a large portion of the territory of every State might be taken from it, for there is scarcely a road in any State which will not be used for the transportation of the mail.  A new field for legislation and internal government would thus be opened.

From this view of the subject I think we may fairly conclude that the right to adopt and execute a system of internal improvement, or any part of it, has not been granted to Congress under the power to establish post-offices and post-roads; that the common roads of the country only were contemplated by that grant and are fully competent to all its purposes.