case would not be exclusive. Suppose a state should prohibit a sale of any of the lands within its boundaries by its own citizens, for any public purposes indispensable for the Union, either military or civil, would not congress possess a constitutional right to demand, and appropriate land within the state for such purposes, making a just compensation? Exclusive jurisdiction over a road is one thing; the right to make it is quite another. A turnpike company may be authorized to make a road; and yet may have no jurisdiction, or at least no exclusive jurisdiction over it.
§ 1142. The supposed silence of the Federalist[1] proves nothing. That work was principally designed to meet objections, and remove prejudices. The post-office establishment in its nature, and character, and purposes, was so generally deemed useful and convenient, and unexceptionable, that it was wholly unnecessary to expound its value, or enlarge upon its benefits.
§ 1143. Such is a summary of the principal reasoning on each side of this much contested question. The reader must decide for himself, upon the preponderance of the argument.
§ 1144. This question, as to the right to layout and construct post-roads, is wholly distinct from that of the more general power to lay out and make canals, and military and other roads. The latter power may not exist at all; even if the former should be unquestionable. The latter turns upon a question of implied power, as incident to given powers.[2] The former turns upon the true interpretation of words of express grant. Nobody doubts, that the words "establish post-roads," may, without violating their re-