To the House of Representatives of the United States:
I communicate herewith a report from the Secretary of War, containing the information called for by the resolution of the House of Representatives of the 17th July, 1848, in relation to the number of Indians in Oregon, California, and New Mexico, the number of military posts, the number of troops which will be required in each, and "the whole military force which should constitute the peace establishment."
I have seen no reason to change the opinion expressed in my message to Congress of the 6th July, 1848, transmitting the treaty of peace with Mexico, that "the old Army, as it existed before the commencement of the war with Mexico, especially if authority be given to fill up the rank and file of the several corps to the maximum number authorized during the war, will be a sufficient force to be retained in service during a period of peace."
The old Army consists of fifteen regiments. By the act of the 13th of May, 1846, the President was authorized, by "voluntary enlistments, to increase the number of privates in each or any of the companies of the existing regiments of dragoons, artillery, and infantry to any number not exceeding 100," and to "reduce the same to 64 when the exigencies requiring the present increase shall cease." Should this act remain in force, the maximum number of the rank and file of the Army authorized by it would be over 16,000 men, exclusive of officers. Should the authority conferred by this act be continued, it would depend on the exigencies of the service whether the number of the rank and file should be increased, and, if so, to what amount beyond the minimum number of 64 privates to a company.
Allowing 64 privates to a company, the Army would be over 10,000 men, exclusive of commissioned and noncommissioned officers, a number which, it is believed, will be sufficient; but, as a precautionary measure, it is deemed expedient that the Executive should possess the power of increasing the strength of the respective corps should the exigencies of the service be such as to require it. Should these exigencies not call for such increase, the discretionary power given by the act to the President will not be exercised.
It will be seen from the report of the Secretary of War that a portion of the forces will be employed in Oregon, New Mexico, and Upper California; a portion for the protection of the Texas frontier adjoining the Mexican possessions, and bordering on the territory occupied by the Indian tribes within her limits. After detailing the force necessary for these objects, it is believed a sufficient number of troops will remain to afford security and protection to our Indian frontiers in the West and Northwest and to occupy with sufficient garrisons the posts on our northern and Atlantic borders.
I have no reason at present to believe that any increase of the number of regiments or corps will he required during a period of peace.
JAMES K. POLK.
James K. Polk, Special Message Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/201687