The present case affords a striking and forcible illustration of this principle. Let it be granted that you have a right, as proprietor, by the permission of the States, to make a road through their territories, can it ever follow, as an incident to this mere power of appropriating the public money, that you may exercise jurisdiction over this very road, as a sovereign? If you could, the incident is as much greater than the principal, as sovereign is superior to individual power. It does follow that you can keep the road in repair, by appropriations, in the same manner that you have made it; but this is the utmost limit of your power. What, Sir? Exclusive jurisdiction over the road, for its preservation, and for the punishment of all offenders who travel upon it, and that as an incident to the mere power of expending your money upon its construction! The idea is absurd. Under the power given to Congress “to establish post offices and post roads,” the Federal Government possess the undoubted right of converting any road already constructed, within any State of this Union, into a post road. Let it also be granted, for the sake of the argument, that they possess the power, independently of the will of the States, to construct as many post roads throughout the Union as they think proper, and to keep them in repair; does it follow that they can establish toll-gates upon such roads? Certainly not. What is the nature of the powder conferred upon Congress? It is a mere right to carry and to protect the mails. It is confined to a single purpose—to the transportation of the mail, and the punishment of offences which violate that right. This is the sole object of the power—the sole purpose for which it was called into existence. Over some post roads, the mail is carried once per day, and over others once per week. With what justice can it be contended that this right of passage for a single purpose—this occasional use of the roads within the different States for post roads—vests in Congress the power of closing up these roads against all the citizens of those States, at all times, until they have paid such a toll as we think proper to impose. Let me present the naked argument of gentlemen before their own eyes. Congress have the right, under the Constitution, “to establish post offices and post roads.” As an incident they possess the power of constructing post roads. As another incident to this right of passage for a single purpose they possess the power to assume jurisdiction over all post roads in the different States, and prevent any person from passing over them, unless upon such terms as they may prescribe. This would, indeed, be construction construed. I would like the gentleman from Virginia (Mr. Mercer) to furnish the committee with an answer to this argument. If I were to grant to that gentleman a right of passage, for a particular purpose only, over a road which belonged to me, what would be my