The defective character of this line of defense and the mistake underlying its acceptance were strongly emphasized after the overthrow of Zollicoffer at Mill Springs and the pushing forward of General Thomas's forces to more southerly points. This movement placed a threatening force on the right flank of the Confederate line of defense. Nevertheless, the Confederate War Department clung to its mistaken policy. It lived at that time in a fool's paradise in which facts counted for little in comparison with theories, and in which optimism was expected to serve the purpose of guns and brigades and defensive works.
When at the end of January, 1862, the War Department asked General Beauregard to go to that region as second in command under General Albert Sydney Johnston, it confidently assured him that the troops under General Johnston's command exceeded seventy thousand in number. On his arrival there General Beauregard found that in fact these widely and dangerously scattered forces numbered less than forty-five thousand and that the several parts could not possibly be made to support each other. He found also that the strength in fortification, in guns and in men, which should have been concentrated mainly in Forts Henry and Donelson, had been largely wasted at Columbus, a position naturally indefensible or defensible by a small as easily as by a large force. He found that vast quantities of precious stores had been warehoused there in face of the fact that Columbus was the most northerly and the most exposed point on the entire defensive line.
When General Beauregard joined General Johnston and made his study of conditions, he pointed out all these defects in the line and all the dangers they involved. General Beauregard had, since the battle of Manassas, developed an aggressive tendency which he had strangely lacked in the earlier months of his career as a general. He had grown into a real general. He therefore proposed to General Johnston an instant offensive movement.
Here it is important for the reader clearly to understand the situation.
General Polk, commanding the Confederates at Columbus, was threatened by a superior force under General Pope in Missouri, on the other side of the river. General Johnston's position at Bowling Green was threatened by a distinctly superior army under General Buell which lay scarcely more than a two days' march to the north and east. Moreover the position of Bowling Green was already in effect turned by Thomas's advance from eastern Kentucky towards eastern Tennessee. In the meanwhile General Grant, supported by the gunboats, was in possession of Paducah and threatening to advance with 15,000 men for the reduction of Fort Henry and Fort Donelson.
The Confederate forces were scattered beyond all possibility of effective coöperation except by a concentration in advance involving a radical change in the scheme and line of defense. There were at that time about 14,000 Confederate effectives at Bowling Green; about 5,500 at Forts Henry and Donelson; about 8,000 near Clarksville; and about 15,000 at and near Columbus. Other detached forces at various points swelled the total of the Confederate forces in Kentucky and Tennessee to about 45,000 fighting men.
Grant was threatening the river forts with 15,000 men. Pope had 30,000 men or more in southeast Missouri, threatening Columbus. Buell had a large and rapidly increasing army, numbering from 40,000 to 60,000 men (overestimated by Beauregard at 75,000 or 80,000) at Bacon's Creek, within striking distance, forty miles, of Bowling Green.
It was obviously easy for Pope to occupy Polk at Columbus and for Buell to engage Johnston at Bowling Green with an overwhelming force, while Grant should advance to the assault of Forts Henry and Donelson.
Buell, with his army of 40,000 or 50,000 men, might easily have overwhelmed Johnston's 14,000 at Bowling Green. Pope could have so far engaged Polk at Columbus as to prevent the detachment even of a squad from that quarter for Johnston's reinforcement. Grant in the meanwhile could make his advance with 15,000 men—to be reinforced presently to 27,000—and the gunboats, against Forts Henry and Donelson, defended as those works were by no more than 5,500 men.
It was Beauregard's urgent advice to withdraw all but garrison forces from Columbus, Bowling Green and Clarksville, and to concentrate an overmastering force for resistance to Grant in front of Fort Donelson.