The navy under Porter was all it could be, during the entire campaign.  Without its assistance the campaign could not have been successfully made with twice the number of men engaged.  It could not have been made at all, in the way it was, with any number of men without such assistance.  The most perfect harmony reigned between the two arms of the service.  There never was a request made, that I am aware of, either of the flag-officer or any of his subordinates, that was not promptly complied with.

The campaign of Vicksburg was suggested and developed by circumstances.  The elections of 1862 had gone against the prosecution of the war.  Voluntary enlistments had nearly ceased and the draft had been resorted to; this was resisted, and a defeat or backward movement would have made its execution impossible.  A forward movement to a decisive victory was necessary.  Accordingly I resolved to get below Vicksburg, unite with Banks against Port Hudson, make New Orleans a base and, with that base and Grand Gulf as a starting point, move our combined forces against Vicksburg.  Upon reaching Grand Gulf, after running its batteries and fighting a battle, I received a letter from Banks informing me that he could not be at Port Hudson under ten days, and then with only fifteen thousand men.  The time was worth more than the reinforcements; I therefore determined to push into the interior of the enemy’s country.

With a large river behind us, held above and below by the enemy, rapid movements were essential to success.  Jackson was captured the day after a new commander had arrived, and only a few days before large reinforcements were expected.  A rapid movement west was made; the garrison of Vicksburg was met in two engagements and badly defeated, and driven back into its stronghold and there successfully besieged.  It looks now as though Providence had directed the course of the campaign while the Army of the Tennessee executed the decree.

Upon the surrender of the garrison of Vicksburg there were three things that required immediate attention.  The first was to send a force to drive the enemy from our rear, and out of the State.  The second was to send reinforcements to Banks near Port Hudson, if necessary, to complete the triumph of opening the Mississippi from its source to its mouth to the free navigation of vessels bearing the Stars and Stripes.  The third was to inform the authorities at Washington and the North of the good news, to relieve their long suspense and strengthen their confidence in the ultimate success of the cause they had so much at heart.

Soon after negotiations were opened with General Pemberton for the surrender of the city, I notified Sherman, whose troops extended from Haines’ Bluff on the left to the crossing of the Vicksburg and Jackson road over the Big Black on the right, and directed him to hold his command in readiness to advance and drive the enemy from the State as soon as Vicksburg surrendered.  Steele and Ord were directed to be in readiness to join Sherman in his move against General Johnston, and Sherman was advised of this also.  Sherman moved promptly, crossing the Big Black at three different points with as many columns, all concentrating at Bolton, twenty miles west of Jackson.