he national courts can only hear causes
which originate in maritime affairs.

[Footnote g: As for instance, all cases of piracy.]

The Constitution comprises under one head almost all the cases which by
their very nature come within the limits of the Federal courts. The
rule which it lays down is simple, but pregnant with an entire system of
ideas, and with a vast multitude of facts. It declares that the judicial
power of the Supreme Court shall extend to all cases in law and equity
arising under the laws of the United States.

Two examples will put the intention of the legislator in the clearest
light:

The Constitution prohibits the States from making laws on the value
and circulation of money: If, notwithstanding this prohibition, a State
passes a law of this kind, with which the interested parties refuse to
comply because it is contrary to the Constitution, the case must come
before a Federal court, because it arises under the laws of the United
States. Again, if difficulties arise in the levying of import duties
which have been voted by Congress, the Federal court must decide the
case, because it arises under the interpretation of a law of the United
States.

This rule is in perfect accordance with the fundamental principles of
the Federal Constitution. The Union, as it was established in 1789,
possesses, it is true, a limited supremacy; but it was intended that
within its limits it should form one and the same people. *h Within
those limits the Union is sovereign. When this point is established
and admitted, the inference is easy; for if it be acknowledged that
the United States constitute one and the same people within the bounds
prescribed by their Constitution, it is impossible to refuse them the
rights which belong to other nations. But it has been allowed, from the
origin of society, that every nation has the right of deciding by its
own courts those questions which concern the execution of its own laws.
To this it is answered that the Union is in so singular a position
that in relation to some matters it constitutes a people, and that in
relation to all the rest it is a nonentity. But the inference to be
drawn is, that in the laws relating to these matters the Union possesses
all the rights of absolute sovereignty. The difficulty is to know what
these matters are; and when once it is resolved (and we have shown
how it was resolved, in speaking of the means of determining the
jurisdiction of the Federal