General Prentiss seems here to have become separated from a large portion of his command. The division fell into confusion; fragments of brigades and regiments continued the fight, but there was no longer concert of action or continuity of lines of defence. Most of the troops drifted back behind the new lines that were being formed; many, as they continued an isolated struggle, were surrounded and taken prisoners.
Practically, by 10 o'clock the division was gone. General Prentiss and the few troops that surrounded him maintained a detached position some hours longer, till they were completely cut off and surrounded; and the Rebels signalized their success by marching three regiments, with a division general, as prisoners, to their rear.
By 10 o'clock, however, this entire division was virtually _hors du combat_. A deep gap in our front line was made, the Rebels had nearly pierced through, and were only held back by McArthur's Brigade and the rest of W. H. L. Wallace's Division, which hurried over to its assistance.
For the present, let us leave them there. They held the line from this time until four.
We left Sherman's Brigade maintaining a confused fight, Hildebrand's about gone, Buckland's and McDowell's holding their ground more tenaciously. The firing aroused McClernand's Division. At first they supposed it to be a mere skirmish; perhaps even only the irregular discharge of muskets by guards and pickets, to clean out their guns--a practice which, to the disgrace of our discipline be it said, was well nigh universal--and rendered it almost impossible at any time to know whether firing meant anything at all, beyond ordinary disorder of our own soldiers. But the continued rattle of musketry soon undeceived them, and almost as soon the advance of the Rebels, pouring after Hildebrand, was upon them.
The division, it will be remembered, lay a short distance in the rear, and with one brigade stretching out to the left of Sherman's line. Properly speaking, merely from the location of the camp, McClernand did not belong to the front line at all. Two-thirds of his division were entirely behind Sherman. But as the latter fell back, McClernand had to bear the shock of battle.