Jackson, July 17.
--Our army quietly withdrew from
Jackson at 10 o'clock last night to prevent being flanked on the right.
The sick and wounded, and all the stores, have been removed.
The enemy did not discover the retreat until daylight, and have made no effort to pursue.
Our army is in line of battle here.
[This dispatch should doubtless be dated Brandon, Miss, which is this side of Pearl river.
Grant now has a sufficient supply of water from this river for his troops, which he has been fighting for during the past two weeks]