The first plan attempted was to divide the army, Sherman taking part of it from Memphis and down the Mississippi on transports, while Grant should move southward along the line of the Mississippi Central Railroad to cooperate with Sherman, his movements to be governed by the efforts of the scattered Confederate forces in Mississippi to block him. But the whole plan was destined to failure, through the energies of General Van Dorn and others of the Confederate army near Grant's line of communication. The authorities at Washington preferred the river move upon Vicksburg, as the navy could keep the line of communication open. The stronghold now stood within a strong line of defense extending from Haynes' Bluff on the Yazoo to Grand Gulf on the Mississippi, thirty miles below Vicksburg. To prepare for Sherman's attack across the swamps of the Yazoo, Admiral Porter made several expeditions up that tortuous stream to silence batteries and remove torpedoes. In one of these he lost one of the Eads ironclads, the _Cairo_, blown up by a torpedo, and in another the brave Commander Gwin, one of the heroes of Shiloh, was mortally wounded. Sherman, with an army of thirty-two thousand men, left Memphis on December 20th, and landed a few days later some miles north of Vicksburg on the banks of the Yazoo. On the 29th he made a daring attack in three columns on the Confederate lines of defense at Chickasaw Bayou and suffered a decisive repulse. His loss was nearly two thousand men; the Confederate loss was scarcely two hundred. Two hundred feet above the bayou, beyond where the Federals were approaching, towered the Chickasaw Bluffs, to which Pemberton hastened troops from Vicksburg as soon as he learned Sherman's object. At the base of the bluff, and stretching away to the north and west were swamps and forests intersected by deep sloughs, overhung with dense tangles of vines and cane-brakes. Federal valor vied with Confederate pluck in this fight among the marshes and fever-infested jungle-land. One of Sherman's storming parties, under General G. W. Morgan, came upon a broad and deep enlargement of the bayou, McNutt Lake, which interposed between it and the Confederates in the rifle-pits on the slopes and crest of the bluff. In the darkness of the night of December 28th, the Federal pontoniers labored to construct a passage-way across the lake. When morning dawned the weary pontoniers were chagrined to discover their well-built structure spanning a slough leading in another direction than toward the base of the bluff. The bridge was quickly taken up, and the Federals recommenced their labors, this time in daylight and within sight and range of the Southern regiments on the hill. The men in blue worked desperately to complete the span before driven away by the foe's cannon; but the fire increased with every minute, and the Federals finally withdrew.