In regard to the last branch of the inquiry made by the resolution of
the Senate, I have to observe that the Constitution declares that "the
President shall take care that the laws be faithfully executed," and
that "he shall be Commander in Chief of the Army and Navy of the United
States, and of the militia of the several States when called into the
actual service of the United States," and that "Congress shall have
power to provide for calling forth the militia to execute the laws of
the Union, suppress insurrections, and repel invasions." From which it
appears that the Army and Navy are by the Constitution placed under the
control of the Executive; and probably no legislation of Congress could
add to or diminish the power thus given but by increasing or diminishing
or abolishing altogether the Army and Navy. But not so with the militia.
The President can not call the militia into service, even to execute the
laws or repel invasions, but by the authority of acts of Congress passed
for that purpose. But when the militia are called into service in the
manner prescribed by law, then the Constitution itself gives the command
to the President. Acting on this principle, Congress, by the act of
February 28, 1795, authorized the President to call forth the militia to
repel invasion and "suppress insurrections against a State government,
and to suppress combinations against the laws of the United States, and
cause the laws to be faithfully executed." But the act proceeds to
declare that whenever it may be necessary, in the judgment of the
President, to use the military force thereby directed to be called
forth, the President shall forthwith, by proclamation, command such
insurgents to disperse and retire peaceably to their respective abodes
within a limited time. These words are broad enough to require a
proclamation in all cases where militia are called out under that act,
whether to repel invasion or suppress an insurrection or to aid in
executing the laws. This section has consequently created some doubt
whether the militia could be called forth to aid in executing the laws