191. The seat of government in the first instance was New York. It was then removed to Philadelphia, and, finally, in 1800, to Washington, a district of ten miles square, called the District of Columbia, having been ceded to the United States by Maryland and Virginia. Having exclusive jurisdiction within the District, Congress possess the means of protecting themselves from insult or interruption, without dependence on the state authorities, who might, in particular exigencies, be unable or unwilling to defend them.

192. As the District of Columbia is not a state in the sense of the Constitution, the citizens cannot send Representatives to Congress, nor vote for President or Vice-President of the United States. Recently [1871], however, a territorial government was established for them, with the right to a delegate in Congress.

Jurisdiction over Forts, &c.

193. If a place is purchased in any state, with the consent of its legislature, for the erection of a fort, magazine, arsenal, dockyard, or other needful buildings, then Congress possesses exclusive jurisdiction over such place, and neither civil nor criminal process, issued under the authority of the state, can be executed therein, unless the state expressly reserves

that privilege. Moreover, the inhabitants of such place cease to be inhabitants of the state, and cannot exercise any civil or political rights under the laws

of the state.

194. On the other hand, if a purchase of territory is made by the United States in any state for public purposes, without the consent of its legislature, then the jurisdiction of the state over such territory remains full and complete. It has not the right, however, to tax such territory.

General Power of Congress.

195. Had the Constitution made no provision to that effect, it would have been implied that Congress might employ the means necessary to execute the powers with which they were invested. But it has not been left to implication: the Constitution expressly authorizes Congress to make all laws which shall be necessary and proper for carrying into execution the foregoing powers, and all other powers vested by the Constitution in the government of the United States, or in any department or officer thereof.

196. Congress has no power under this clause of the Constitution, except to provide the means of executing the powers vested in the government of the United States, or in any department or officer thereof. If the means be appropriate to this end, if they are not prohibited, and are consistent with the

letter and spirit of the Constitution, then they are authorized.

Concurrent powers of Legislation in the States.

197. It is important to observe that the powers which the Constitution confides to Congress are not necessarily exclusive. It is only in cases where the Constitution, in express terms, grants an exclusive authority to Congress, or the nature of the authority requires that it should be exclusively exercised by Congress, that the subject is taken from the state legislatures.

198. It is believed that there are only three cases where the authority of Congress is exclusive: First, when it is made exclusive in express terms; secondly, when a power is confided to Congress, and the states are prohibited from exercising a like power; thirdly, when a power. is granted to Congress to which a similar power in the states would be absolutely and totally contradictory and repugnant.

199. In all other cases the states retain concurrent authority with Congress, subject, however, to two limitations. One is, that if the state legislation conflicts with that of Congress, then it is void, because the laws of the United States made in pursuance of the Constitution are supreme. The other is, that where, from the nature of the power, its exercise at

the same time by both Congress and the states would be inconsistent, then the legislation of Congress, in pursuance of that power, absolutely suspends the legislative power of the states over the same subject. Thus, Congress are authorized to establish uniform laws on the subject of bankruptcy, but the states may pass bankrupt laws, provided there be no act of Congress in force establishing a uniform law on that subject. In this instance, it is not the mere existence of the power, but its exercise, which is incompatible with the exercise of the same power by the states. When Congress passes a uniform law, the partial laws of the states must yield to it.

I

POWERS DENIED TO CONGRESS.

200. We have seen in the preceding pages what Congress may do. The next step leads us to consider what they may not do.

The Slave Trade.

201. In the first place, the migration or importation of such persons as any of the states existing at the time of the adoption of the Constitution should think proper to admit, were not to be prohibited by the Congress prior to the year one thousand eight hundred and eight; but a tax or duty might be imposed on such importation not exceeding ten dollars for each person.

202. The object of this clause was to prevent Congress from interdicting the slave trade prior to the year 1808. At the time the Constitution was framed, there was a strong feeling in several of the states in favor of that trade, and in deference to that feeling Congress were inhibited to abolish it prior to the year above named. Congress, however, at an early day prohibited American citizens from carrying on the traffic between foreign countries; and they