While so unsatisfactory a condition of affairs existed in the first great military field east of the Alleghanies, the outlook was quite as unpromising both in the second—­between the Alleghanies and the Mississippi—­and in the third—­west of the Mississippi.  When the Confederates, about September 1, 1861, invaded Kentucky, they stationed General Pillow at the strongly fortified town of Columbus on the Mississippi River, with about six thousand men; General Buckner at Bowling Green, on the railroad north of Nashville, with five thousand; and General Zollicoffer, with six regiments, in eastern Kentucky, fronting Cumberland Gap.  Up to that time there were no Union troops in Kentucky, except a few regiments of Home Guards.  Now, however, the State legislature called for active help; and General Anderson, exercising nominal command from Cincinnati, sent Brigadier-General Sherman to Nashville to confront Buckner, and Brigadier-General Thomas to Camp Dick Robinson, to confront Zollicoffer.

Neither side was as yet in a condition of force and preparation to take the aggressive.  When, a month later, Anderson, on account of ill health turned over the command to Sherman, the latter had gathered only about eighteen thousand men, and was greatly discouraged by the task of defending three hundred miles of frontier with that small force.  In an interview with Secretary of War Cameron, who called upon him on his return from Fremont’s camp, about the middle of October, he strongly urged that he needed for immediate defense sixty thousand, and for ultimate offense “two hundred thousand before we were done.”  “Great God!” exclaimed Cameron, “where are they to come from?” Both Sherman’s demand and Cameron’s answer were a pertinent comment on McClellan’s policy of collecting the whole military strength of the country at Washington to fight the one great battle for which he could never get ready.

Sherman was so distressed by the seeming magnitude of his burden that he soon asked to be relieved; and when Brigadier-General Buell was sent to succeed him in command of that part of Kentucky lying east of the Cumberland River, it was the expectation of the President that he would devote his main attention and energy to the accomplishment of a specific object which Mr. Lincoln had very much at heart.

Ever since the days in June, when President Lincoln had presided over the council of war which discussed and decided upon the Bull Run campaign, he had devoted every spare moment of his time to the study of such military books and leading principles of the art of war as would aid him in solving questions that must necessarily come to himself for final decision.  His acute perceptions, retentive memory, and unusual power of logic enabled him to make rapid progress in the acquisition of the fixed and accepted rules on which military writers agree.  In this, as in other sciences, the main difficulty, of course, lies in applying fixed theories to variable conditions.