Bombproofs of the 45th Illinois in Union siege line. Shirley House in background is only surviving wartime building in the park. From Photographic History of the Civil War.
For protection against artillery fire, the Confederate troops dug bombproofs in the reverse slope of their fortified ridge. From these dugouts, bulwarked by heavy timbers, trenches connected with the fortifications, affording the besieged some degree of relaxation in reading or playing cards a few yards from the front line. To defend against surprise night attacks, they were forced to sleep on their arms in the trenches.
At night the unending bombardment from Porter’s fleet provided the troops of both armies with an awesome pyrotechnic display. Especially popular with the pickets were the giant 13-inch mortar shells whose sputtering fuses described a tremendously high arc in the blackness before disappearing into the city. It was a “wonderful spectacle,” one soldier remembered, “to see the fuse from the shells—and you could see them plainly—the comet or star-like streams of fire and then hear them coming down into the doomed city. We used to watch them while on picket at night.”
Fort Hill, on the Confederate left flank above Vicksburg, commanding the bend of the Mississippi.
South Fort, on the Confederate right flank below Vicksburg, overlooking the Mississippi.
Each of Porter’s mortar boats carried one of these giant 17,000-pound mortars which hurled 200-pound shells into Vicksburg throughout the campaign and siege. Courtesy National Archives.