Chattanooga headquarters of General Rosecrans during the siege. Courtesy National Archives.
The movement of the Eleventh and Twelfth Army Corps from the Army of the Potomac to Tennessee eclipsed all other such troop movements by rail up to that time. It represented a high degree of cooperation between the railroads and the government and was a singular triumph of skill and planning. It also shows the great importance the War Department attached to the Chattanooga campaign.
The troops began to entrain at Manassas Junction and Bealton Station, Va., on September 25, and 5 days later on September 30 the first trains arrived at Bridgeport, Ala. The route traveled was by way of Washington, D. C.; Baltimore, Md.; Bellaire and Columbus, Ohio; Indianapolis, Ind.; Louisville, Ky.; Nashville, Tenn.; and Bridgeport, Ala. Several major railroad lines, including the Baltimore and Ohio, Central Ohio, Louisville and Nashville, and Nashville and Chattanooga were involved.
Not all of the troops, however, made such good time as the first trains, and for the majority of the infantry the trip consumed about 9 days. The movement of the artillery, horses, mules, baggage, and impedimenta was somewhat slower, but by the middle of October, all were in the vicinity of Bridgeport ready to help break the siege.
These two corps under Maj. Gen. Joseph Hooker, comprising 20,000 troops and more than 3,000 horses and mules, traveled 1,157 miles. Differences in the railroad gauges hampered the movement, but most of the changes in gauge occurred at river crossings which had no bridges and the troops had to detrain at these points anyway.
Confederate cavalry raids, bent on destroying the railroad bridges and otherwise interfering with the reinforcing effort, imposed a more serious difficulty, but, except for delaying the latter part of the movement a few days, the raids were ineffective.
At the beginning of the siege, the Union Army had large supply trains in good condition and transporting supplies seemed feasible. But early in October rain began to fall and the roads became almost impassable. To make the situation more critical Bragg sent Wheeler to harass and destroy the Union supply trains as they moved over Walden’s Ridge on their trips to and from Bridgeport. Wheeler destroyed hundreds of wagons and animals and it was not long before the Union soldier received less and less food. Wagon horses and mules and artillery horses were on a starvation diet and many died each day.
Command of the two hostile armies had undergone a considerable change during the siege period. Grant received orders to meet “an officer of the War Department” at Louisville, Ky. He proceeded by rail to Indianapolis, Ind., and just as his train left the depot there, en route to Louisville, it was stopped. A message informed Grant that Secretary of War Stanton was coming into the station and wished to see him. This was the “officer” from the War Department who gave Grant command of the newly organized Military Division of the Mississippi. Thomas replaced Rosecrans. McCook and Crittenden had previously been relieved of their commands and their corps consolidated into the Fourth Corps under command of Granger. Stanton accompanied Grant to Louisville and there the two spent a day reviewing the situation.
In Bragg’s camp, Polk was relieved of his command, and Lt. Gen. William J. Hardee rejoined the army. Bragg’s army was reorganized into three corps commanded by Longstreet, Hardee, and Breckinridge.