The powers conferred by the constitution on Congress are as follows. It may impose taxes, duties, imposts, and excises, which, however, must be uniform on all the inhabitants of the States. It may borrow money on the credit of the United States of America. It may regulate commerce, lay down a general rule of naturalization, regulate the coinage, and punish offences relating to it. It has also the care of post-offices and post roads, and the superintendence of copyright, both in books and in inventions. It has jurisdiction over offences committed at sea. It has the power of war and peace, the control of the United States’ army and navy, and military law. It regulates the calling out and the organization of the State militia for common purposes. It is the sole government of the district of Columbia, in which Washington is situated; and it has power to make laws binding on the individual citizens of every State in the Union, for the purpose of executing any of these powers. All sovereign powers not included under these heads are reserved to the individual States, but they are expressly prohibited from exercising their sovereignty in certain ways. No State may enter into alliances, or make peace or war, or emit bills of credit, or make anything but gold and silver coin a tender in payment of debts, or pass any bill of attainder, _ex post facto_ law, or law impairing the obligation of contracts, or grant any title of nobility. It has not been uncommon in Europe for States to give themselves constitutions which have been ridiculed in this country (often not reasonably) on the ground that the provisions which had the largest sound were in fact mere empty words. This cannot be said of the American constitution. Its practical efficiency is secured by the only means which can secure it—the institution of independent courts of justice bound to put a judicial construction upon its provisions, and armed with the powers necessary to make that construction prevail in fact. These courts treat the constitution as they would treat any other law, and freely exercise the power of deciding whether the acts of the individual States, or even those of Congress itself, are unconstitutional and therefore illegal. The courts in question are divisible into three classes. In the first class stands the Supreme Court of the United States; in the second are the circuit courts; and in the third, the district courts. The Supreme Court has original jurisdiction in diplomatic cases, in admiralty and maritime cases, in cases arising between individual States, and in cases in which the United States are a party. It also entertains appeals from the circuit and district courts. The circuit courts and district courts are local, and closely resemble each other in the general character of their jurisdiction, though the circuit courts are the more important of the two. They entertain all civil causes above 500 dollars in which the United States is a party, or in which an alien