The deafening roar of the cannon that characterized the beginning of the day's battle was followed by the rattle of musketry, so continuous that no ear could distinguish one shot from another. Nelson's division of Buell's army was the first to engage the Confederates. Nelson commanded the Federal left wing, with Hardee and Breckinridge immediately opposed to him. The Union center was under the command of Generals McCook and Crittenden; the right wing was commanded by McClernand, with Hurlbut next, while Sherman and Lew Wallace occupied the extreme right. The Confederate left wing was commanded by the doughty Bragg and next to him was General Polk. Shiloh Church was again the storm center and in it General Beauregard made his headquarters. Hour after hour the columns in blue and gray surged to and fro, first one then the other gaining the advantage and presently losing it. At times the smoke of burning powder enveloped the whole field and hid both armies from view. The interesting incidents of this day of blood would fill a volume. General Hindman of the Southern side had a novel experience. His horse was struck by a bursting shell and torn to a thousand fragments. The general, thrown ten feet high, fell to the ground, but leaped to his feet unhurt and asked for another horse. Early in the afternoon, Beauregard became convinced that he was fighting a losing battle and that it would be the part of prudence to withdraw the army before losing all. He thereupon sent the members of his staff to the various corps commanders ordering them to prepare to retreat from the field, at the same time making a show of resuming the offensive. The retreat was so skilfully made, the front firing-line being kept intact, that the Federals did not suspect it for some time. Some hours before nightfall the fighting had ceased. The Federals remained in possession of the field and the Confederates were wading through the mud on the road to Corinth. It was a dreary march for the bleeding and battered Confederate army. An eye-witness described it in the following language: