ew taken of the other enumerated powers, for had it been
intended to include in the right to declare war, by way of incident,
any right of jurisdiction or legislation over territory within a State,
it would have been done as to fortifications, magazines, arsenals,
dockyards, and other needful buildings. By specifically granting the
right as to such small portions of territory as might be necessary for
these purposes and on certain conditions, minutely and well defined,
it is manifest that it was not intended to grant it as to any other
portion on any condition for any purpose or in any manner whatsoever.

It may be said that although the authority to exercise exclusive
legislation in certain cases within the States with their consent may
be considered as a prohibition to Congress to exercise like exclusive
legislation in any other case, although their consent should be granted,
it does not prohibit the exercise of such jurisdiction or power within
a State as would be competent to all the purposes of internal
improvement. I can conceive no ground on which the idea of such a power
over any part of the territory of a State can be inferred from the power
to declare war. There never can be an occasion for jurisdiction for
military purposes except in fortifications, dockyards, and the like
places. If the soldiers are in the field or are quartered in garrisons
without the fortifications, the civil authority must prevail where they
are. The government of the troops by martial law is not affected by it.
In war, when the forces are increased and the movement is on a greater
scale, consequences follow which are inseparable from the exigencies
of the state. More freedom of action and a wider range of power in the
military commanders, to be exercised on their own responsibility, may
be necessary to the public safety; but even here the civil authority
of the State never ceases to operate. It is also exclusive for all
civil purposes.

Whether any power short of that stated would be adequate to the purposes
of internal improvement is denied. In the case of territory one
government must prevail for all the purposes intended by the grant.
The jurisdiction of the United States might be modified in such manner
as to admit that of the State in all cases and for all purposes not
necessary to the execution of the proposed power; but the right of the
General Government must be complete for all the purposes above stated.
It must extend to the