Sappers at work before Port Hudson.in burrows such as these the Federal soldiers worked incessantly from June 14th until the surrender of Port Hudson in an effort to undermine “the citadel,” the strongest fortification in the Confederate lines near the Jackson road. Cotton-bales roped about were used as sap-rollers to protect the men from sharpshooters. The heat under the semi-tropical sun was terrible, drying up the brooks and distilling miasma from the pestilential swamp near by. The illness and mortality among the Federals were enormous, and yet the men worked on the saps uncomplainingly, and by July 7th the central one had been carried within seventeen feet of the ditch of the fort, and a storming party of a thousand volunteers had been organized to assault the works as soon as the two heavily charged mines should be sprung. That very day came the word that Vicksburg had fallen, and the work of the sappers and miners was useless.