“3d.  By properly fortifying on the Mississippi River, the force to guard it from Port Hudson to New Orleans can be reduced to ten thousand men, if not to a less number.  Six thousand more 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 return, 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 Missouri.  If however, you think the force here stated too small to hold the territory regarded as necessary to hold possession of, I would say concentrate at least twenty-five thousand men of your present command for operations against Mobile.  With these and such additions as I can give you from elsewhere, lose no time in making a demonstration, to be followed by an attack upon Mobile.  Two or more iron-clads will be ordered to report to Admiral Farragut.  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 Department, you will know best about the matter.  It is intended that your movements shall be co-operative with movements 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.

“U.  S. Grant, Lieutenant-General. 
“Major-general N. P. Banks.”

Major-General Meade was instructed that Lee’s army would be his objective point; that wherever Lee went he would go also.  For his movement two plans presented themselves:  One to cross the Rapidan below Lee, moving by his right flank; the other above, moving by his left.  Each presented advantages over the other, with corresponding objections.  By crossing above, Lee would be cut off from all chance of ignoring Richmond or going north on a raid.  But if we took this route, all we did would have to be done whilst the rations we started with held out; besides, it separated us from Butler, so that he could not be directed how to cooperate.  If we took the other route, Brandy Station could be used as a base of supplies until another was secured on the York or James rivers.  Of these, however, it was decided to take the lower route.

The following letter of instruction was addressed to Major-General B. F. Butler: 

“Fort Monroe, Virginia, April 2, 1864.

“General:-In the spring campaign, which it is desirable shall commence at as early a day as practicable, it is proposed to have cooperative action of all the armies in the field, as far as this object can be accomplished.