From the beginning of the war the Confederacy had been fully alive to the vital importance of the Mississippi River. From Columbus to the Gulf it had been fortified and protected by every means which the skill and resources of the South could afford. Forts Jackson and St. Philip guarded its lower part, and covered New Orleans; though these were nullified by the daring of Farragut, and the city fell early in the war. But there were half a dozen other "Gibraltars" on its long line--Columbus, Island No. 10, Fort Pillow, Memphis, Vicksburg, and Port Hudson. Foote had used up Island No. 10, after the rebels were compelled to evacuate Columbus. Fort Pillow and Memphis had yielded before the persuasive force of the naval squadron, and only Vicksburg and Port Hudson were left to dispute the passage of the great river. Between these two points the enemy, depending almost wholly upon Texas for its supplies of cattle, ferried them over, and by the line of railroads from Vicksburg to Charleston, not yet approached by the national arms, were enabled still to send food to all their armies in the east and south. Bold Farragut had passed the batteries at Port Hudson with his squadron, and sailed up to Vicksburg, more than five hundred miles from the Gulf. Here he had bombarded the strong works which protected the city; but as they were planted on high bluffs, all the advantage was in favor of the enemy, and the result was not a success. The troops which accompanied him under General Williams attempted to open the canal, which was to form a new bed for the river, and enable the fleet to pass the city. But this scheme also failed, and though a part of the squadron ran the gantlet of the batteries, and joined the naval force above the city, the expedition was obliged to return to New Orleans to escape the diseases incident to the climate. About the 1st of November Grant initiated his movement in the direction of Vicksburg. Commencing on the line of defence which had just been wrested from the rebels, there was a railroad extending from Memphis to Grenada. Fifty miles east of Memphis, from near La Grange, on the railroad extending east and west, was another line to the south--the Mississippi Central--which also went to Grenada, where the two roads meeting extended to Jackson, forty miles east of Vicksburg, and thence to New Orleans. Both of these roads crossed the Tallahatchie River, a branch of the Yazoo, which flowed into the Mississippi a few miles above Vicksburg. Grant's plan was to move down upon these lines of railway, depending upon them in his rear for supplies. Pemberton, who was in command of Vicksburg and the forces which were covering it in the State of Mississippi, was holding the railroad, and made the Tallahatchie River his line of defence. On the 4th of November, Grant took possession of La Grange, near the Central Railroad, driving the Confederate advance to Holly Springs, about twenty miles farther south.