Farragut's fleet, now anchored below Vicksburg, comprised the flagship _Hartford_, the sloops-of-war _Brooklyn_ and _Richmond_, the corvettes _Iroquois_ and _Oneida_, and six gunboats. Porter had joined with the _Octorara, Miami_, six other steamers, and seventeen of the mortar schooners. The orders of the government were peremptory that the Mississippi should be cleared. The Confederates held the river by a single thread. The fall of Memphis and the ruin of the famous river-defence fleet left between St. Louis and the Gulf but a solitary obstruction. This was Vicksburg.
Vicksburg stand at an abrupt turn, where within ten miles the winding river doubles upon itself, forming on the low ground opposite a long finger of land, barely three quarters of a mile wide. Opposite the extreme end of this peninsula, known as De Soto, the bluff reaches the highest point attained along the whole course of the river, the crest standing about 250 feet above the mean stage of water. Sloping slowly toward the river, the bluff follows it with a diminished altitude for two miles. Here stands the town of Vicksburg, then a place of about ten thousand inhabitants. Below the town the bluffs draw away from the river until, about four miles beyond the bend, their height diminishes to about 150 feet. For the defence of this line, as has been already seen, a formidable series of batteries had been constructed, extending from the bluff at the mouth of Chickasaw Bayou on the north to Warrenton on the south. These batteries now mounted twenty-six heavy guns, served by gunners comparatively well trained and instructed, and supported against an attack by land by about 6,000 infantry under Lovell. Almost simultaneously with the arrival of Farragut and Williams, came Breckinridge with his division, augmenting the effective force of the defenders to not less than 10,000. On the 30th of May Beauregard evacuated Corinth and drew back to Tupelo; Halleck did not follow; and so 35,000 Confederates were now set free to strengthen Vicksburg. Thus defended and supported Vicksburg was obviously impregnable to any attack by the combined forces of Farragut and Williams. On the 28th of June, Van Dorn arrived and took command of the Confederate forces.