The city had been under Union naval attack before. Admiral David Farragut moved up the river after his capture of New Orleans and on May 18, 1862, demanded the surrender of Vicksburg. Farragut had insufficient troops to force the issue, and he moved back to New Orleans. He returned with a flotilla in June 1862, but their attempts (June 26 -- 28) to bombard the fortress into surrender failed. They shelled Vicksburg throughout July and fought some minor battles with a few Confederate vessels in the area, but their forces were insufficient to attempt a landing, and they abandoned attempts to force the surrender of the city. Farragut investigated the possibility of bypassing the fortified cliffs by digging a canal across the neck of the river 's bend, the De Soto Peninsula. On June 28, Brig. Gen. Thomas Williams, attached to Farragut 's command, began digging work on the canal by employing local laborers and some soldiers. Many of the men fell victim to tropical diseases and heat exhaustion, and the work was abandoned by July 24. (Williams was killed two weeks later in the Battle of Baton Rouge).
the union admiral that led the campaign against new orleans
Admiral David Farragut