His fleet battered after the engagement with the Arkansas, Davis was a little testy about Farragut’s failure to support him at Vicksburg. With Farragut heading south and taking Gen. Thomas R. Williams’ troops with him, Davis lacked the personnel to maintain his precarious position at Vicksburg. He decided to retreat 175 miles upriver to Helena, Arkansas.
UNION AND CONFEDERATE NAVIES IN THE WAR OF THE REBELLION. SERIES I VOLUME 23. NAVAL FORCES ON WESTERN WATERS FROM APRIL 12 TO DECEMBER 31, 1862. p.269-272.
Extract from diary of Flag-Officer Davis, U. S. Navy.
Mississippi River, July 31,  .
In my last letter I believe I gave you a short account of our last attempt to destroy the Arkansas. It was a failure in every way. There was a want of cooperation, most unaccountable, on the part of Commodore Farragut, by which one important vessel was not brought into action and by which the support of his squadron was withheld. I was informed by Flag-Officer Farragut immediately after the last attack on the Arkansas that he intended to move down the river at once, in obedience to orders from the Department, and at the same moment I learned from report that General Williams was to accompany him with the troops under his command.
I wrote to General Williams, urging him to remain and keep open communication above and below Vicksburg by railroad, the means for constructing which were at hand. He replied that his orders obliged him to go, and that without them he would be compelled to move on account of the disabled condition of his command. He had brought with him 3,200 men, of Which 2,400 were dead or in the hospital. He could only muster 800 effective men and officers.
His departure rendered it necessary that I should abandon the position I then held, because it gave the enemy the possession of the point from the ditch down. General Williams has, in making the canal, converted it into a means of defense by constructing a continued breastwork and rifle pit on the lower border and introducing an angle where the levee crossed the canal on the upper border, so as to enfilade it.
It was, therefore, no longer safe for my hospital, commissary, and ordnance boats to lie at the bank as they had done. I therefore moved up with my whole command to the mouth of the Yazoo. Vicksburg being thus abandoned above and below by the fleets and the Army, I had to determine on my next step.
I had allowed the ram Sumter to go do down with Farragut, not only to assist in the attack on the Arkansas, but to assist also in maintaining the blockade of that vessel below; and in the same manner and with the same motive I consented to the Essex going down.
I supposed that Commodore Farragut might go down. He told me that he had urged the Department to allow him to do so, but it never entered my head that I should be deserted by the Army, and it was my expectation to blockade the town on both sides, keeping up the communication between the two detachments of my squadron across the neck.
My squadron had been reduced to a comparatively weak condition. Both the vessels engaged with the Arkansas in the Yazoo River had been sent to Cairo for repairs, and having lost the Essex and the Sumter I was reduced to the Benton, the Cincinnati in a sinking condition, the Louisville, and the ram General Bragg. Sickness had made sudden and terrible havoc with my people. It came, as it were, all at once.
Taking into consideration all these things, I determined to return up the river as far as Helena, and am on my way there now. This decision is my own. I talked the matter over with one or two persons, but called no council of war. The responsibility is my own, and it will not worry me the least in the world if it is not approved of.
It was not to be expected that I could take the city of Vicksburg with my squadron only without troops, and this being so I am as well at Helena as at any point lower down. As we approach Helena I am satisfied, from the reports received from the transports, towing vessels, etc., that if we had remained a week longer at Vicksburg I should not have had engineers nor firemen enough to bring the vessels up. As it is we have depended very much on the contrabands to do the work in front of the fires.