WASHINGTON, May 7, 1864.

Major General E. R. S. CANBY,

Washington:

GENERAL: The Secretary of War directs that you immediately repair to the Military Division of West Mississippi and assume the direction of all military operations in the Departments of the Gulf and of Arkansas.

You will perceive from the dispatches sent to and received from Generals Grant, Sherman, Steele, and Banks that the main object of the recent military operations west of the Mississippi River was the occupation of Red River, so as to shorten our line of defense, secure the navigation of the Mississippi from interruption from the western side, and to prevent any large forces from penetrating into Arkansas, Missouri, or the Indian Territory. This would also enable us to dispense with the present difficult the expensive line of defense on the Arkansas River, and to diminish the military posts at Helena and New Madrid.

The failure to carry out this plan has, it is believed, resulted from General Banks' delay to co-operate in time with the movements of Generals Steele and A. J. Smith, and his meeting and fighting the enemy by detachments instead of his whole force in mass. You will perceive by Lieutenant-General Grant's dispatches that he has no confidence in General Banks' military capacity, and has consequently directed him to turn over the command of his troops to the senior officer in the field and return to New Orleans. General Grant at one time ordered a part of the troops of the Department of the Gulf to New Orleans to operate against Mobile, but this project has been given up, and all troops in your division will be retained from duty west of the Mississippi.

You will also receive herewith authority to employ, in case of necessity, any troops on the east bank of the river belonging to General Sherman's command. It is presumed, however, that General Sherman left there only such forces as were deemed necessary for securing the navigation of the river. None should therefore be removed except in case of emergency, and after you have satisfied yourself that the garrisons left are sufficient for the security of the places occupied.

The Secretary of War directed some time since that Major-General Reynolds be placed in command of New Orleans and its defenses. This order will not be construed to prevent you from replacing General Reynolds, if you want him with you in the field or for any other command. You are authorized by the Secretary of War to remove from your command any officer whom you may deem inefficient or incompetent, reporting to the Adjutant-General your reasons for so doing.

It is understood that General Banks has lost a very considerable portion of his land transportation. You will advise with the Quartermaster-General in regard to the best means of supplying this deficiency. It is hoped, however, that you will be able to support your troops in part upon the country passed over. The enemy lives almost entirely upon the country, and we must hereafter imitate his example and avoid so far as possible encumbering our movable columns with too large trains. Existing orders give you all necessary authority on this subject. You will perceive from a perusal of official dispatches that General Banks' course in scattering his troops