s been done in clear and explicit terms, first by granting the
power to Congress, and secondly by prohibiting the exercise of it by
the States. "Congress shall have a right to declare war." This is the
language of the grant. If the right to adopt and execute this system
of improvement is included in it, it must be by way of incident only,
since there is nothing in the grant itself which bears any relation to
roads and canals. The following considerations, it is presumed, prove
incontestably that this power has not been granted in that or any other
manner.

The United States are exposed to invasion through the whole extent of
their Atlantic coast by any European power with whom we might be engaged
in war--on the northern and northwestern frontier on the side of Canada
by Great Britain, and on the southern by Spain or any power in alliance
with her. If internal improvements are to be carried to the full extent
to which they may be useful for military purposes, the power as it
exists must apply to all the roads of the Union, there being no
limitation to it. Wherever such improvements may facilitate the march
of troops, the transportation of cannon, or otherwise aid the operations
or mitigate the calamities of war along the coast or in any part of the
interior they would be useful for military purposes, and might therefore
be made. The power following as an incident to another power can be
measured as to its extent by reference only to the obvious extent of the
power to which it is incidental. So great a scope was, it is believed,
never given to incidental power.

If it had been intended that the right to declare war should include
all the powers necessary to maintain war, it would follow that nothing
would have been done to impair the right or to restrain Congress from
the exercise of any power which the exigencies of war might require.
The nature and extent of this exigency would mark the extent of the
power granted, which should always be construed liberally, so as to be
adequate to the end. A right to raise money by taxes, duties, excises,
and by loan, to raise and support armies and a navy, to provide for
calling forth, arming, disciplining, and governing the militia when
in the service of the United States, establishing fortifications and
governing the troops stationed in them independently of the State
authorities, and to perform many other acts is indispensable to the
maintenance of war--no war with any great power