and to make rules for the regulation of the land and naval forces; to provide for calling out the militia to suppress insurrections and repel invasions, and to command this militia while actually employed in the service of the United States.  The several states, however, train their own militia and appoint the officers.  Congress may also establish a uniform rule of naturalization, and uniform laws on the subject of bankruptcies.  It also exercises exclusive control over the District of Columbia,[23] as the seat of the national government, and over forts, magazines, arsenals, dockyards, and other needful buildings, which it erects within the several states upon land purchased for such purposes with the consent of the state legislature.

[Footnote 23:  Ceded to the United States by Maryland and Virginia.]

[Sidenote:  The “Elastic Clause.”] Congress is also empowered “to make all laws which shall be necessary and proper for carrying into execution the foregoing powers and all other powers vested by this Constitution in the government of the United States, or in any department or office thereof.”  This may be called the Elastic Clause of the Constitution; it has undergone a good deal of stretching for one purpose and another, and, as we shall presently see, it was a profound disagreement in the interpretation of this clause that after 1789 divided the American people into two great political parties.

[Sidenote:  Powers denied to the states.] [Sidenote:  Paper currency.] The national authority of Congress is further sharply defined by the express denial of sundry powers to the several states.  These we have already enumerated.[24] There was an especial reason for prohibiting the states from issuing bills of credit, or making anything but gold and silver coin a tender in payment of debts.  During the years 1785 and 1786 a paper money craze ran through the country; most of the states issued paper notes, and passed laws obliging their citizens to receive them in payment of debts.  Now a paper dollar is not money, it is only the government’s promise to pay a dollar.  As long as you can send it to the treasury and get a gold dollar in exchange, it is worth a dollar.  It is this exchangeableness that makes it worth a dollar.  When government makes the paper dollar note a “legal tender.” i.e., when it refuses to give you the gold dollar and makes you take its note instead, the note soon ceases to be worth a dollar.  You would rather have the gold than the note, for the mere fact that government refuses to give the gold shows that it is in financial difficulties.  So the note’s value is sure to fall, and if the government is in serious difficulty, it falls very far, and as it falls it takes more of it to buy things.  Prices go up.  There was a time (1864) during our Civil War when a paper dollar was worth only forty cents and a barrel of flour cost $23.  But that was nothing to the year 1780, when the paper dollar issued