Colonel Charles E. Hooker, Confederate Military History, a library of Confederate States Military History: Volume 12.2, Mississippi
Clement Anselm Evans, Ed.

[159] bold attack at Chickasaw Bayou, his fearful repulse and heavy loss—all demonstrated how hard it was, indeed, almost impossible, successfully to attack the city, even with superior numbers, from the river front. When General Grant commenced the landing of his force at Young's Point, in full view through glasses from Vicksburg, it clearly demonstrated that he had determined to surround the city, land his troops below Vicksburg and assail it from the rear. The feint on Snyder's Bluff seemed to have deluded the Confederate commander at Vicksburg. The troops at Snyder's Bluff were finally sent to reinforce the gallant Bowen at Port Gibson; but when they had marched half way they were met by the news that Bowen had been defeated there and Grant had made a successful landing of his forces on the eastern bank of the river and was rapidly marching into the interior, and these forces were ordered back to Vicksburg. Had Bowen been reinforced in time by the guns and troops at Snyder's Bluff, and had made his resistance to Grant's army at the crossing of the river, it may be that the fall of Vicksburg would never have been recorded in history.

On the 14th day of June, 1863, General Grant admitted he had 71,000 men. In a subsequent letter, published in Vol. XXIV, part 3, War Records, General Grant said, ‘I have this day received 8,000 men in addition to those already received.’ Hurlbut was in command at Memphis, and shipped transport after transport crowded with troops to reinforce General Grant at the siege. It may safely be said that in addition to the overwhelming numbers with which he met General Pemberton at Champion's Hill and Big Black, his forces after he laid siege to Vicksburg had been increased at least 40,000 men. General Grant believed up to within a few days of the surrender of Vicksburg that Joseph E. Johnston would attack him at Snyder's Bluff, crossing at Messenger's or Byrdsong's ferry on the Big Black north of the railroad.