Learning that Gen. Jos. E. Johnston was coming to Pemberton's assistance, he rapidly pushed between them to Jackson, that, while holding back Johnston with his right hand, with his left he might drive Pemberton into Vicksburg, and thus capture his whole army. Pursuing this design, he defeated Johnston at _Jackson_ (May 14), and then, turning to the west, drove Pemberton from his position at _Champion Hills_ (May 16); next at _Big Black River_ (May 17); and in seventeen days after crossing the Mississippi, shut up Pemberton's army within the works at Vicksburg. Two desperate assaults upon these having failed, the Union troops began to throw up intrenchments. Mines and countermines were now dug. Not one of the garrison could show his head above the works without being picked off by the watchful riflemen. A hat, held above a port-hole, in two minutes was pierced with fifteen balls. Shells reached all parts of the city, and the inhabitants burrowed in caves to escape the iron storm. The garrison, worn out by forty-seven days of toil in the trenches, surrendered on the 4th of July. _The Effect_.--This campaign cost the Confederates five battles, the cities of Vicksburg and Jackson, thirty-seven thousand prisoners, ten thousand killed and wounded, and immense stores. On the fall of Vicksburg, Port Hudson, which had been besieged by General Banks for many weeks, surrendered. [Footnote: To escape the fiery tempest which constantly swept over Port Hudson, and to provide for the safety of their magazines, the garrison dug deep recesses in the bluffs, approached by steps cut out of the earth. An eye-witness says: "As we rode along the earthworks inside, after the siege, it was curious to mark the ingenious ways in which they had burrowed holes to shelter themselves from shell and from the intolerable rays of the sun; while at work, they must have looked like so many rabbits popping in and out of their warrens."] The Mississippi was now open to the Gulf, and the Confederacy cut in twain. One great object of the North was accomplished. THE WAR IN TENNESSEE AND GEORGIA. Rosecrans, after the battle of Murfreesboro, made no formal movement until June, With sixty thousand men, he then marched against Bragg. By threatening his communications, he compelled Bragg to evacuate Chattanooga (Sept. 8). [Footnote: One objection which Rosecrans opposed to a forward movement was his inferiority in cavalry. This was removed in July, when General John H. Morgan, with about four thousand Confederate cavalry, crossed the Ohio at Brandenburg, swept around Cincinnati, and struck the river again near Parkersburg. During his entire route, he was harassed by militia. At this point he was overtaken by his pursuers, while gunboats in the river prevented his crossing. Nearly the entire force was captured. Morgan escaped, but was finally taken and confined in the penitentiary at Columbus. Four months afterward, he broke jail and reached Richmond in safety.]