1 While the battle of Shiloh was a Union victory, nevertheless it was dearly won, and could easily have been a defeat. Even at that time the men in discussing it, pointed out some of the mistakes made by the Union forces. I wish to point out how the day at Shiloh was almost lost to the Union Army. In the first place, when the different commanders called out the troops under arms at 6 o'clock on Friday evening, April 4th, they kept them in line until midnight, when, since the immediate danger was past, they ordered them to return to their quarters. Then it was that a great mistake was made, for instead of sending the men back to camp, they should have been put to work, every man with shovel, pick or axe, digging trenches, throwing up breastworks and fortifying their camps. Thus by the morning of the 6th they would have had two or three lines of works. That this was not done must of course be charged to General Sherman. Each man behind the works would have been equal to five men in the open. General Prentiss’ men, protected in the old, sunken roadway, in making their attack upon us. proved the worth of a man protected, to one out in the open. The mistake cost the Union army more than a thousand men, besides those captured.
In the second place, when the Union army was attacked on that Sunday morning, there were but four regiments in line of battle and ready for the assault of the Confederates. The officers did not succeed in forming a continuous line of battle until late in the day. Regiments and brigades would march to the front and form in line, but they were usually unsupported by troops on the right and left at the same time. This enabled the Confederates to come in on the flanks and the rear, thus compelling our forces to fall back or be captured. This continued till late in the afternoon, when Webster succeeded in forming a continuous line of artillery, supported by all arms. This, together with the arrival of Buell's brigade, which formed a line on the left, saved the day to the Union cause for all time to come. — A. G. D.
Source: Alexander G. Downing, Edited by Olynthus B., Clark, Downing’s Civil War Diary, p. 45