William A. Crafts, Life of Ulysses S. Grant: His Boyhood, Campaigns, and Services, Military and Civil.

But all day, while the battle raged, the banks of the river had been crowded with stragglers from the front, some slightly wounded, some never in the battle, but all full of stories of surprise, overwhelming forces, terrible disasters, horrible slaughter, and all the exaggerations of men unused to battle, and of cowards who deserted their posts. Seen from the rear, it looked as if the contest was resulting in utter and irreparable defeat; and colored by these unworthy and untrue reports, the country was made to see the first day's battle at Shiloh as a disaster, which was only saved from utter completeness by Buell's arrival. Buell himself, who arrived in advance of his troops, apparently took a similar view, and as soon as he met Grant inquired, “What preparations have you made for retreating, general?” But he was quickly interrupted by Grant, who exclaimed, with firmness, “I haven't despaired of whipping them yet!” He knew how the brave men at the front were resisting the enemy, and he knew that if he held out through that day, the victory could be won the next, and so he never thought of retreat. Such was his determined spirit in all his campaigns, and in all his battles.

After the battle, it is said — though the anecdote is not so authentic as the above statement — that Buell, in criticising the position of Grant's army, with the Tennessee in their rear, again recurred to the question of retreat, and asked, “Where would you have retreated, general, if beaten?”