nations in Europe have established posts, and for mutual convenience have stipulated a free passage for the posts arriving on their frontiers through their territories. It is probable, that the constitution intended nothing more by this provision, than to enable congress to do by law, without consulting the states, what in Europe can be done only by treaty or compact. It was thought necessary to insert an express provision in the constitution, enabling the government to exercise jurisdiction over ten miles square for a seat of government, and of such places, as should be ceded by the states for forts, arsenals, and other similar purposes. It is incredible, that such solicitude should have been expressed for such inconsiderable spots, and yet, that at the same time, the constitution intended to convey by implication the power to construct roads throughout the whole country, with the consequent right to use the timber and soil, and to exercise jurisdiction over them. It may be said, that, unless congress have the power, the mail-roads might be obstructed, or discontinued at the will of the state authorities. But that consequence does not follow; for when a road is declared by law to be a mail-road, the United States have a right of way over it; and, until the law is repealed, such an interest in the use of it, as that the state authorities could not obstruct it.[1] The terms of the constitution are perfectly satisfied by this limited construction, and the power of congress to make whatever roads they may please, in any state, would be a most serious inroad upon the rights and jurisdiction of the states. It never could have been contemplated.[2]
