Active operations again began toward the end of November, when the rivers were rising from the autumnal rains. The great object of the combined Union forces was the reduction of Vicksburg, upon which the authorities at Washington preferred to move by way of the river, as it gave, under the convoy of the navy, an easy line of communication not liable to serious interruptions. The Confederate line of which Vicksburg was the centre then faced the river, the right resting on Haines's Bluff, a strongly fortified position twelve miles away, near to and commanding the Yazoo; while the left was on the Mississippi at Grand Gulf, sixty miles below Vicksburg by the stream, though not over thirty by land. The place, in the end, was reduced much in the same way as Island No. 10; the troops landing above it on the opposite bank, and marching down to a point below the works. The naval vessels then ran by the batteries and protected the crossing of the army to the east bank. A short, sharp campaign in the rear of the city shut the Confederates up in their works, and the Union troops were able to again secure their communications with the river above the town. There were, however, grave risks in this proceeding from the time that the army abandoned its water-base, adding to its line of communication thirty miles of bad roads on the river bank, and then throwing itself into the enemy's country, leaving the river behind it. It was therefore preferred first to make every effort to turn the position from the north, through the Yazoo country. [Illustration: MISSISSIPPI VALLEY--HELENA TO VICKSBURG.]