General A's army. The sixty-second Article of War directs that in such case the officer highest in rank by commission there on duty shall command the combined force, "unless otherwise specially directed by the President of the United States." But the officer highest in rank is General B or C, who must therefore command (according to the sixty-second Article of War), unless otherwise specially directed by the President. But neither General B nor C can take the command, for the President has otherwise directed by making them subordinate to General A, under the act of April E. And there is no provision of law whatever that would give the command to General D, notwithstanding the fact that he is senior to General A, for he is junior to both General B and General C, hence the combined force can have no commander unless it be General A. I think therefore it is clear that the law of April 4, 1862, in giving through the President's order an officer command over his seniors by commission, abrogates the sixty-second Article of War so far as it relates to himself and other officers of the same grade who are not commanding under the law of April 4.
The second question is not so clear. There is an apparent conflict between the sixty-second Article of War, and the act of April 4, 1864, which seems to leave a combined force such as I have supposed without a commander provided for it by law. But in my opinion this conflict is not real. The Article of War itself gives the President the power to direct otherwise than according to the general rule, which I understand to mean simply that he may direct the senior not to assume command of all the forces but leave each under its own commander, and the act of April 4 gives him the additional power to assign a junior officer to the command whenever military operations may require the presence of two or more officers of the same grade in the same field. The President, in pursuance of this law, has assigned a commander to each of three armies or departments (the armies consisting simply of the troops serving in those departments and determined not by the President but by the General-in-Chief of all the armies, or other superior officer having direction of military operations in the three departments), and has assigned a general to command the three departments, combined under the name of a military division, and to direct to operations of the combined armies as general-in-chief. Under the authority conferred by the act of Congress, and the discretion given him in the Article of War, he has provided in advance for the very case in point by naming three army commanders to be next in authority and responsibility to the general-in-chief in the order of their rank, and superior in both authority and responsibility to all other officers; and has given to the general-in-chief authority to combine or separate, detach or unite, his three armies, or any part of them, on any field, as in his judgment "military operations may require." The President has assigned in advance the commanders of the forces which military operations may require to be united on any field, and has left it to his generals-in-chief to judge, when, whose, and what forces shall be united. The evident object of the law of April 4, 1862, was to give the President the power to select from all the major-generals of the army those in his judgment most competent to direct the operations of the separate armies, and the power thus given has been habitually exercised. If, when the exigencies of the service require a temporary increase of one of these armies, which is likely to occur only at the most critical periods of a campaign the army commander selected by the President can be superseded by an officer who has never been intrusted with more than a subordinate command, the object of the law is defeated and the President's