by Federal law, that law, and not the State law, is to govern.
It is only when the offense does not happen to be within the purview of
Federal law that the Federal courts are to try and punish him under any
other law. Then resort is to be had to "the common law, as modified and
changed" by State legislation, "so far as the same is not inconsistent
with the Constitution and laws of the United States." So that over this
vast domain of criminal jurisprudence provided by each State for the
protection of its own citizens and for the punishment of all persons who
violate its criminal laws, Federal law, whenever it can be made to
apply, displaces State law. The question here naturally arises, from
what source Congress derives the power to transfer to Federal tribunals
certain classes of cases embraced in this section. The Constitution
expressly declares that the judicial power of the United States "shall
extend to all cases, in law and equity, arising under this Constitution,
the laws of the United States, and treaties made or which shall be made
under their authority; to all cases affecting ambassadors, other public
ministers, and consuls; to all cases of admiralty and maritime
jurisdiction; to controversies to which the United States shall be a
party; to controversies between two or more States, between a State and
citizens of another State, between citizens of different States, between
citizens of the same State claiming lands under grants of different
States, and between a State, or the citizens thereof, and foreign
states, citizens, or subjects." Here the judicial power of the United
States is expressly set forth and defined; and the act of September 24,
1789, establishing the judicial courts of the United States, in
conferring upon the Federal courts jurisdiction over cases originating
in State tribunals, is careful to confine them to the classes enumerated
in the above-recited clause of the Constitution. This section of the
bill undoubtedly comprehends cases and authorizes the exercise of powers
that are not, by the Constitution, within the jurisdiction of the courts
of the United States. To transfer them to those courts would be an
exercise of authority well calculated to excite distrust and alarm on
the part of all the States, for the bill applies alike to all of
them--as well to those that have as to those that have not been engaged
in rebellion.

It may be assumed that this authority is incident to the power granted