General Sherman was instructed to move against Johnston’s army, to break it up, and to go into the interior of the enemy’s country as far as he could, inflicting all the damage he could upon their war resources.  If the enemy in his front showed signs of joining Lee, to follow him up to the full extent of his ability, while I would prevent the concentration of Lee upon him, if it was in the power of the Army of the Potomac to do so.  More specific written instructions were not given, for the reason that I had talked over with him the plans of the campaign, and was satisfied that he understood them and would execute them to the fullest extent possible.

Major-General N. P. Banks, then on an expedition up Red River against Shreveport, Louisiana (which had been organized previous to my appointment to command), was notified by me on the 15th of March, of the importance it was that Shreveport should be taken at the earliest possible day, and that if he found that the taking of it would occupy from ten to fifteen days’ more time than General Sherman had given his troops to be absent from their command, he would send them back at the time specified by General Sherman, even if it led to the abandonment of the main object of the Red River expedition, for this force was necessary to movements east of the Mississippi; that should his expedition prove successful, he would hold Shreveport and the Red River with such force as he might deem necessary, and return the balance of his troops to the neighborhood of New Orleans, commencing no move for the further acquisition of territory, unless it was to make that then held by him more easily held; that it might be a part of the spring campaign to move against Mobile; that it certainly would be, if troops enough could be obtained to make it without embarrassing other movements; that New Orleans would be the point of departure for such an expedition; also, that I had directed General Steele to make a real move from Arkansas, as suggested by him (General Banks), instead of a demonstration, as Steele thought advisable.

On the 31st of March, in addition to the foregoing notification and directions, he was instructed as follows: 

“1st.  If successful in your expedition against Shreveport, that you turn over the defence of the Red River to General Steele and the navy.

“2d.  That you abandon Texas entirely, with the exception of your hold upon the Rio Grande.  This can be held with four thousand men, if they will turn their attention immediately to fortifying their positions.  At least one-half of the force required for this service might be taken from the colored troops.