Long experience has deeply convinced me that a strict construction of the powers granted to Congress is the only true, as well as the only safe, theory of the Constitution.  Whilst this principle shall guide my public conduct, I consider it clear that under the war-making power Congress may appropriate money for the Construction of a military road through the Territories of the United States when this is absolutely necessary for the defense of any of the States against foreign invasion.  The Constitution has conferred upon Congress power “to declare war,” “to raise and support armies,” “to provide and maintain a navy,” and to call forth the militia to “repel invasions.”  These high sovereign powers necessarily involve important and responsible public duties, and among them there is none so sacred and so imperative as that of preserving our soil from the invasion of a foreign enemy.  The Constitution has therefore left nothing on this point to construction, but expressly requires that “the United States shall protect each of them [the States] against invasion.”  Now if a military road over our own Territories be indispensably necessary to enable us to meet and repel the invader, it follows as a necessary consequence not only that we possess the power, but it is our imperative duty to construct such a road.  It would be an absurdity to invest a government with the unlimited power to make and conduct war and at the same time deny to it the only means of reaching and defeating the enemy at the frontier.  Without such a road it is quite evident we can not “protect” California and our Pacific possessions “against invasion.”  We can not by any other means transport men and munitions of war from the Atlantic States in sufficient time successfully to defend these remote and distant portions of the Republic.

Experience has proved that the routes across the isthmus of Central America are at best but a very uncertain and unreliable mode of communication.  But even if this were not the case, they would at once be closed against us in the event of war with a naval power so much stronger than our own as to enable it to blockade the ports at either end of these routes.  After all, therefore, we can only rely upon a military road through our own Territories; and ever since the origin of the Government Congress has been in the practice of appropriating money from the public Treasury for the construction of such roads.

The difficulties and the expense of constructing a military railroad to connect our Atlantic and Pacific States have been greatly exaggerated.  The distance on the Arizona route, near the thirty-second parallel of north latitude, between the western boundary of Texas, on the Rio Grande, and the eastern boundary of California, on the Colorado, from the best explorations now within our knowledge, does not exceed 470 miles, and the face of the country is in the main favorable.  For obvious reasons the Government ought not to undertake