To the Senate of the United States:
In compliance with the resolution of the Senate passed on the 10th instant, requesting me to inform that body, if not incompatible with the public interest, "whether John B. Floyd, whose appointment as Secretary of War was confirmed by the Senate on the 6th of March, 1857, still continues to hold said office, and, if not, when and how said office became vacant; and, further, to inform the Senate how and by whom the duties of said office are now discharged, and, if an appointment of an acting or provisional Secretary of War has been made, how, when, and by what authority it was so made, and why the fact of said appointment has not been communicated to the Senate," I have to inform the Senate that John B. Floyd, the late Secretary of the War Department, resigned that office on the 29th day of December last, and that on the 1st day of January instant Joseph Holt was authorized by me to perform the duties of the said office until a successor should be appointed or the vacancy filled. Under this authority the duties of the War Department have been performed by Mr. Holt from the day last mentioned to the present time.
The power to carry on the business of the Government by means of a provisional appointment when a vacancy occurs is expressly given by the act of February 13, 1795, which enacts--
That in case of vacancy in the office of Secretary of State, Secretary of the Treasury, or of the Secretary of the Department of War, or of any officer of either of the said Departments whose appointment is not in the head thereof, whereby they can not perform the duties of their respective offices, it shall be lawful for the President of the United States, in case he shall think it necessary, to authorize any person or persons, at his discretion, to perform the duties of the said respective offices until a successor be appointed or such vacancy be filled: Provided , That no one vacancy shall be supplied in manner aforesaid for a longer period than six months.
It is manifest that if the power which this law gives had been withheld the public interest would frequently suffer very serious detriment. Vacancies may occur at any time in the most important offices which can not be immediately and permanently filled in a manner satisfactory to the appointing power. It was wise to make a provision which would enable the President to avoid a total suspension of business in the interval, and equally wise so to limit the Executive discretion as to prevent any serious abuse of it. This is what the framers of the act of 1795 did, and neither the policy nor the constitutional validity of their law has been questioned for sixty-five years.
The practice of making such appointments, whether in a vacation or during the session of Congress, has been constantly followed during every Administration from the earliest period of the Government, and its perfect lawfulness has never to my knowledge been questioned or denied. Without going back further than the year 1829, and without taking into the calculation any but the chief officers of the several Departments, it will be found that provisional appointments to fill vacancies were made to the number of 179 from the commencement of General Jackson's Administration to the close of General Pierce's. This number would probably be greatly increased if all the eases which occurred in the subordinate offices and bureaus were added to the count. Some of them were made while the Senate was in session; some which were made in vacation were continued in force long after the Senate assembled. Sometimes the temporary officer was the commissioned head of another Department, sometimes a subordinate in the same Department. Sometimes the affairs of the Navy Department have been directed ad interim by a commodore and those of the War Department by a general. In most, if not all, of the cases which occurred previous to 1852 it is believed that the compensation provided by law for the officer regularly commissioned was paid to the person who discharged the duties ad interim . To give the Senate a more detailed and satisfactory view of the subject, I send the accompanying tabular statement, certified by the Secretary of State, in which the instances are all set forth in which provisional as well as permanent appointments were made to the highest executive offices from 1829 nearly to the present time, with their respective dates.
It must be allowed that these precedents, so numerous and so long continued, are entitled to great respect, since we can scarcely suppose that the wise and eminent men by whom they were made could have been mistaken on a point which was brought to their attention so often. Still less can it be supposed that any of them willfully violated the law or the Constitution.
The lawfulness of the practice rests upon the exigencies of the public service; which require that the movements of the Government shall not be arrested by an accidental vacancy in one of the Departments; upon an act of Congress expressly and plainly giving and regulating the power, and upon long and uninterrupted usage of the Executive, which has never been challenged as illegal by Congress.
This answers the inquiry of the Senate so far as it is necessary to show "how and by whom the duties of said office are now discharged." Nor is it necessary to explain further than I have done "how, when, and by what authority" the provisional appointment has been made; but the resolution makes the additional inquiry the fact of said appointment has not been communicated to the Senate."
I take it for granted that the Senate did not mean to call for the reasons upon which I acted in performing an Executive duty nor to demand an account of the motives which governed me in an act which the law and the Constitution left to my own discretion. It is sufficient, therefore, for that part of the resolution to say that a provisional or temporary appointment like that in question is not required by law to be communicated to the Senate, and that there is no instance on record where such communication ever has been made.
James Buchanan, Special Message Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/202062