I wrote Gen. Banks, giving him specific guidance to concentrate his forces as much as possible and to move against Mobile with haste. This is necessary to coordinate his movements with the rest of the army.
Washington March 31st 1864
Maj. Gen. N. P. Banks Comd.g Dept. of the Gulf,
In addition to the directions sent you by Lieut. Towner, for immediate concentration at New Orleans of all the forces you can spare from the defence of your Dept. preparatory to a move against Mobile, I would now add the following:
1st If successful in your expedition against Shreveport that you turn over the defence of the Red River to Gen. 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, end At least one half of the force required for this service might be taken from the colored troops.
3d By properly fortifying on the Miss. River the force to guard it, from Port Hudson to New Orleans, can be reduced to ten thousand men, if not to a much less number. Six thousand men would then hold all the rest of the territory necessary to hold until active operations can again be resumed West of the river.—According to your last returns this would give you a force of over thirty thousand effective men with which to move against Mobile. To this I expect to add five thousand men from Missou[ri.] If however you think the force here stated too small to hold the territory regar[ded] as necessary to keep possession of I would say concentrate at least twenty-five thousand men of your present com- man[d] for operations against Mobile. With these and such additions as I can give you from elsewhere loose no time in making a demonstration to be followed by an attack, upon Mobile.
Two or more Iron Clads have been will be ordered to report to Admiral Farrigut. This gives him a strong Naval fleet with which to co-operate. You can make your own arrangements with the Admiral for his co-operation and select your own line of approach. My own idea of the matter is that Pascagoula should be your base, but from your long service in the Gulf Dept. you will know best about this matter.
It is intended that your movements shall be co-operative with movements of Armies elsewhere and you cannot now start too soon. All I would now add is that you commence the concentration of your forces at once. Preserve a profound secrecy of what you intend doing and start at the earliest possible moment.
I am General, very respectfully
your obt. svt.
U. S. Grant
Lt. Gen. Comd.g
The Papers of Ulysses S Grant, Vol 10, p 242-3
O.R. I, xxxiv, part 1, p 11