Saturday, 20th—We remained in line of battle all night and early this morning advanced in a line about two miles, when we received orders to march on into Iuka. The rebels retreated during the night, and General Rosecrans’ forces are after them. We learned this morning that a battle had been fought yesterday here by Rosecrans’ forces alone. When we were waiting for the sound of Rosecrans’ cannon, we could not hear them on account of an unfavorable wind. The rebels attacked him and made the fight come off a day before the time set for our capture of them. The Sixteenth Iowa of Crocker’s Brigade had been detached from us and sent forward, being the only regiment of our brigade engaged in the fight. Their loss was fourteen killed. The Fifth Iowa in Rosecrans’ army was trapped in an ambush which was made with a battery masked in green leaves, and lost forty-one killed. The rebels were driven out and left their dead and wounded on the field. Quite a number of our wounded are now being brought into town from the battlefield. Iuka is a nice place with some good buildings. It is well supplied with good water from splendid springs. There is poor farming land around here, it being quite rolling in this part of Tennessee. The timber, mostly pine, is rather scrubby.