The fight between the Southern ironclad and the ships it destroyed, and the contest next day between it and the _Monitor_, have been widely celebrated in song and story. But the real significance of those contests lies rather in that to which they gave birth than in that which in themselves they were. CHAPTER XXIII SHILOH McClellan's advance upon Richmond, in its beginnings at least, antedated the great conflict at Shiloh. But its crisis did not come until much later, nor did it in its early progress involve aught that was of significance in its bearing upon the conduct and outcome of the war. It seems proper therefore to discuss Shiloh and other operations in the Mississippi Valley first, leaving the campaign in Virginia for later consideration. The Confederates, before the fall of Fort Donelson and Fort Henry, were maintaining a line of offensive defense in Kentucky. This line extended from the Big Sandy in the eastern part of the state to Columbus on the Mississippi river in the extreme west. The line was in many respects defective. The Confederate center of operations was at Bowling Green, while the two ends of the defensive line lay much farther north than that. The line thus constituted what in military parlance is known as a reëntering angle. The enemy pushing into such an angle with forces greater than those that defended it or even with an inferior force, had easy choice to attack on either side as he pleased, concentrating at will, while compelling the Confederates to scatter their forces along the whole of an extensive line by way of defending all parts of it equally. It was the original purpose of those who devised this defensive system to correct the fault by pushing their center forward from Bowling Green to Paducah on the Ohio river, nearly fifty miles above the mouth of that stream. Had this been accomplished, it would have made the angle of defense a salient instead of a reëntering one. Let us explain the advantage of this for the benefit of the non-military reader. If the Confederates could have established themselves at Paducah with their lines trending off to the southeast on the one side and to the southwest on the other, they, instead of their enemies, would have had choice of positions in which to concentrate. Assailed at any point it would have been easy for them to throw all possible force quickly to the defense of the threatened position. Grant interfered with all this planning when he moved up the Ohio, and seized upon Paducah, which was quickly fortified so strongly as to render the execution of the scheme thereafter impracticable. From that time forward it was clear that the Confederates must either maintain their line of defense by means of a vast and dangerously unmanageable reëntering angle, or they must withdraw from their two advanced wing points. To do this latter thing would have been to abandon Kentucky completely, and it was no part of the Confederate program to do that.