To the Senate and House of Representatives of the United States:
In order to prosecute the war against Mexico with vigor and success, it is necessary that authority should be promptly given by Congress to increase the Regular Army and to remedy existing defects in its organization. With this view your favorable attention is invited to the annual report of the Secretary of War, which accompanied my message of the 8th instant, in which he recommends that ten additional regiments of regular troops shall be raised, to serve during the war.
Of the additional regiments of volunteers which have been called for from several of the States, some have been promptly raised; but this has not been the case in regard to all. The existing law, requiring that they should be organized by the independent action of the State governments, has in some instances occasioned considerable delay, and it is yet uncertain when the troops required can be ready for service in the field.
It is our settled policy to maintain in time of peace as small a Regular Army as the exigencies of the public service will permit. In a state of war, notwithstanding the great advantage with which our volunteer citizen soldiers can be brought into the field, this small Regular Army must be increased in its numbers in order to render the whole force more efficient.
Additional officers as well as men then become indispensable. Under the circumstances of our service a peculiar propriety exists for increasing the officers, especially in the higher grades. The number of such officers who from age and other causes are rendered incapable of active service in the field has seriously impaired the efficiency of the Army.
From the report of the Secretary of War it appears that about two thirds of the whole number of regimental field officers are either permanently disabled or are necessarily detached from their commands on other duties. The long enjoyment of peace has prevented us from experiencing much embarrassment from this cause, but now, in a state of war, conducted in a foreign country, it has produced serious injury to the public service.
An efficient organization of the Army, composed of regulars and volunteers, whilst prosecuting the war in Mexico, it is believed would require the appointment of a general officer to take the command of all our military forces in the field. Upon the conclusion of the war the services of such an officer would no longer be necessary, and should be dispensed with upon the reduction of the Army to a peace establishment.
I recommend that provision be made by law for the appointment of such a general officer to serve during the war.
It is respectfully recommended that early action should be had by Congress upon the suggestions submitted for their consideration, as necessary to insure active and efficient service in prosecuting the war, before the present favorable season for military operations in the enemy's country shall have passed away.
JAMES K. POLK.
James K. Polk, Message to the Congress Requesting an Increase in the Size of the Regular Army Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/201165