Tuesday, June 23, 1863

Private William Wiley from the 77th Illinois described the Union efforts to tunnel into the Confederate forts.  

Heavy details were mady each day to work in the trenches and do picket duty in the trenches already dug. We soon got our trenches up so near to the rebel forts that they could fire down on our workmen from the top of their works. But our Yankee ingenuity overcame this difficulty by making long rollers or tubes of bamboo canes about as large as sugar hogheads but longer and filling them with cotton and rolling them in front of us as a breast work.  Pushed by hand by Union soldiers digging approach trenches, these large, barrel-shaped devices were known as sap rollers.

To conserve ammunition, Confederate General Pemberton restricted the firing of rebel cannons. To escape the Union shelling, Vicksburg residents dug caves in the hillside for shelter.