As soon as the infantry took position, the men were set industriously to work to strengthen the defences. The first infantry trench between the forts had been a mere rifle-pit two and one half feet deep with the earth heaped in front as it was thrown out, to raise a parapet. Every hour made the line stronger, and work on it was continued till nearly every part of it was a good cover against artillery fire. The critical time was during the 18th of November, when as yet there was practically no cover between the forts. The cavalry was ordered to oppose the most determined resistance to the establishment of close investing lines by the enemy, and Sanders set his men a most inspiring example. He was a classmate of Captain Poe at West Point, and on the night of the 17th he shared Poe's blanket. Before dawn he went to the front, and passed from one to another of the little barricades held by his dismounted troopers. The Confederates increased the vigor of their attacks, and if any of our men were driven back by the hot fire, Sanders would walk deliberately up to the rail-pile and stand erect and exposed till his men rallied to him. For hours he did this, and his life seemed to be charmed, but about the middle of the afternoon he was mortally wounded, and the screen he had so resolutely interposed between the enemy and our infantry digging in the trenches was rolled aside. [Footnote: Paper by General Poe in "Century War Book," vol. iii. p. 737.] The time thus gained had been precious, though it was bought at so high a price. The lines were already safe against a coup de main. [Footnote: Poe's Report, Official Records, vol. xxxi. pt. i. p. 296.]
Longstreet's principal lines were north of Knoxville beyond the railway and the station buildings. He also occupied a line of hills, but pushed forward strong skirmish lines and detachments to cover the making of intrenchments closer to the town. There were frequent bickering combats, but no general engagement. The enemy made efforts to destroy the pontoon bridge by sending down logs and rafts from above. These were met by an iron cable boom stretched across the river above the bridge, borne on wooden floats to keep it at the surface. [Footnote: Century War Book, vol. iii. p. 739.] Several efforts were made to drive Burnside's men from the hills covering the town on the south side of the river, but they were defeated, and communication was kept up with the valley of the French Broad River, and supplies enough were brought in to make it certain that Burnside could not be starved out, although the rations were reduced to the smallest quantity and the fewest elements which would support life.
A week passed thus, Burnside being shut off from all communication with the outer world. The 25th of November came with the almost miraculous storming of Missionary Ridge by the army under Grant at Chattanooga. Bragg retreated southward and Longstreet had no longer a possibility of rejoining him. Yet Burnside knew nothing of it, and did not dream of the more than complete justification his slow defensive campaign was having, in the tout and demoralization of the Confederate army in Georgia in Longstreet's absence. The latter was now forced to attack the fortifications or to raise the siege of Knoxville. He knew, at least by rumor, what Burnside was ignorant of,--not only the defeat of Bragg, but that a force was already moving from Grant's army to the relief of Knoxville. Bragg had also sent to him a staff officer with exhortations to prompt action. For a day or two Longstreet tried to attract Burnside's attention to the south of the river and to other parts of the lines, and then on the 28th prepared a desperate assault upon the great salient of Fort Sanders.
The artillery in the fort was under the command of Lieutenant Samuel N. Benjamin, Second U. S. Artillery, whose battery of twenty-pounder Parrotts had done good service at South Mountain and Antietam. The infantry was of Ferrero's division of the Ninth Corps. There was a slight abatis in front of the fort, and on the suggestion of Mr. Hoxie, an officer of the railway, some old telegraph wire left at the depot was used by Captain Poe to make an entanglement by fastening it between small stumps of a grove which had been felled along the slope northwest of the bastion at the salient. Longstreet's plan of assault was to attack the northwest angle of the fort with two columns of regiments, consisting of Wofford's and Humphrey's brigades of McLaws's division. Anderson's brigade was to attack the infantry trench a little east of the fort. Longstreet's instructions were to make the assault at break of day on the 29th. The columns were to move silently and swiftly without firing and endeavor to carry the parapet by the bayonet. [Footnote: Longstreet's Report, Official Records, vol. xxxi. pt. i. p. 461.] The determined advance of the enemy's rifle pits by his skirmishers in the night of the 28th gave warning of what was to be expected. The morning of the 29th was damp and foggy, but the watchful pickets detected the formation of the enemy's columns. About six o'clock the Confederate batteries opened a heavy fire on the fort, which did not reply, ammunition being too precious to be wasted. In about twenty minutes the cannonade ceased and the columns moved to the assault. The fire of our lines was concentrated upon them, and they lost heavily; but they kept on, somewhat disordered by the entanglement as well as by their losses, and came to the ditch. No doubt its depth and the high face of the parapet surprised them, for they had no scaling ladders. They jumped into the ditch and tried to scramble up the slope of the earthwork. Some got to the top, only to be shot down or captured. The guns flanking the ditch raked it with double charges of canister. Shells were lighted and thrown as hand-grenades into the practically helpless crowd below. Those who had not entered the ditch soon wavered and fell back, at first sullenly and slowly, then in despair running for life to cover. Those who remained and could walk surrendered and were marched to the southwest angle of the fort, where they were brought within the lines.
The remnants of the broken columns were rallied behind their outer lines, but no effort was made to renew the assault. They had done all that was possible for flesh and blood. The casualties in the assault had been about 1000, whilst within the fortifications only 13 killed and wounded were reported. [Footnote: Official Records, vol. xxxi. pt. i. pp. 277, 278, 344, 461, 487, 490, 519, 520.] Buckner's division had joined Longstreet a day or two before the assault, but took no active part in it. Their absence from Missionary Ridge still further reduced Bragg's army, whilst it did not give to Longstreet any practical benefit. The division of the Confederate forces had thus proved to be a great military mistake. Its only chance had been in a swift attack upon Burnside and a prompt return, and this chance had vanished with the delays in the railroad transportation of Longstreet's men to Sweetwater. Prudence dictated that the expedition should be abandoned on the 13th of November; but the fear of seeming vacillating, a weakness of second-rate minds as great as vacillation itself, had made Bragg order the column forward. Burnside's well-conducted retreat, on the other hand, had lured Longstreet forward, and the patient endurance of a siege had kept the enemy in front of Knoxville, and even led to the further depletion of Bragg by the detachment of Buckner, giving to Grant the very opportunity he desired. The good fortune of the National commander culminated at Missionary Ridge. Soldiers believe in good luck quite as much as in genius, and follow a leader whose star is in the ascendant with a confidence which is the guaranty of victory. Great opportunities, however, come to all. The difference between a great soldier and an inferior one is that the great man uses his opportunities to the full, and so fortune seems to be in league with him. When Grant had driven Bragg back on Dalton, the latter could realize what he had lost by his errors. It was now impossible for Longstreet to rejoin him. It was even doubtful if Wheeler's cavalry could do so. The whole National army was between the widely separated Confederate wings, and nothing was left to Longstreet but a humiliating march back to Lee by way of the upper Holston and the headwaters of the James River. Pride delayed it, and the depth of winter favored the delay; but it was a foregone conclusion from the hour that Wood's and Sheridan's divisions crowned Missionary Ridge.
For two weeks there had been no communication between Burnside and the outer world. Lincoln had been full of anxiety, but had found some comfort in the reports from Cumberland Gap that cannonading was still heard in the direction of Knoxville. It proved that Burnside held out, and gave additional earnestness to the President's exhortation to hurry a column to his relief immediately after Grant's victory. Grant needed no urging. A report had reached him that Burnside still was confident on the 23d, and had supplies for ten or twelve days on the scale of short rations he was issuing. On the very evening of his success he wrote to Sherman, "The next thing now will be to relieve Burnside." He directed Thomas to detach Granger's Corps, and this with part of the Army of the Tennessee would make a column of 20,000 men to march at once for Knoxville under Granger's command. Three days passed, and Grant, being dissatisfied that the relieving column was not already far on its way, directed Sherman on the 29th to take command in person and push it energetically toward Burnside. [Footnote: Official Records, vol. xxxi. pt. ii. pp. 45, 49; Sherman's Memoirs, vol. i. pp. 366, 368.] Sherman immediately went forward, and on the 1st of December he was over the Hiwassee River, approaching Loudon. He telegraphed Grant that he would let Burnside hear his guns on the 3d or 4th at farthest; but he added what throws much light on the feeling of military men in regard to campaigning in East Tennessee. In his frank and familiar style he said, "Recollect that East Tennessee is my horror. That any military man should send a force into East Tennessee puzzles me. Burnside is there and must be relieved; but when relieved, I want to get out and he should come out too." [Footnote: Official Records, vol. xxxi. pt. iii. p. 297.] From a strictly military point of view this was sound; but Burnside had been sent there more from political than from military reasons, and it was now too late to think of letting the loyal mountaineers return under Confederate rule.
Meanwhile at Knoxville Burnside was closely watching the evidences of Longstreet's purposes and eagerly listening for news from Chattanooga. On the 1st of December wagon trains began to move eastward from the besiegers' camp, and on the 3d and 4th more of them, so that it became probable that Longstreet was about to raise the siege. In the night of the 3d Captain Audenried, Sherman's aide-de-camp, came into Knoxville from the south, having made a long circuit with a small body of cavalry, from Sherman's camp, which on the night of the 2d was forty miles from the city by the direct road. Colonel Long, commanding Sherman's cavalry, had selected part of his best mounted men for the expedition, and Audenried had accompanied him. The good news of Sherman's approach was thus made certain, and it was evident that Longstreet's information was earlier than Burnside's. The Confederate camps were evacuated on the night of the 4th, and on the 5th Burnside, sending a detachment to follow up Longstreet's retreat toward the east, sent one of his staff with an escort in the other direction to meet Sherman. The messenger from Burnside met the head of the relieving column at Marysville, a day's march for infantry. Sherman halted his little army, and wrote Burnside that he felt disposed to stop, "for a stern chase is a long one," since Longstreet had retreated. He rode in to Knoxville the next day and consulted with Burnside. He was evidently dubious of any advantage from a pursuit of Longstreet, and Burnside's disposition was to avoid urging any comrade to undertake an unpleasant task for his sake. He therefore cordially assisted Sherman in solving his doubts in favor of taking back all his troops except Granger's Fourth Corps, and wrote a letter of warm thanks for the prompt march to his relief, adding his opinion that the Fourth Corps would make him strong enough to meet Longstreet, and that it was advisable for Sherman to rejoin Grant with the rest. [Footnote: Official Records, vol. xxxi. pt. ii. p. 36.] This was accordingly done, and Sherman was free to give his attention to a winter campaign toward the Gulf, from which he hoped important results.
Granger did not relish the prospect of a protracted absence from the Army of the Cumberland, and protested in vigorous and long dispatches to Thomas, to Grant, to Burnside, to Sherman, and later to Foster, [Footnote: Id., pt. iii. pp. 358, 365, 391-393; Sherman's Memoirs, vol. i. p. 368.] but with no effect, except that Grant was displeased with his original reluctance to march to Burnside's relief as well as with these protests. The result showed itself in the spring, when Granger was relieved from the command of the corps, which was conferred upon Howard.
The raising of the siege brought Burnside into communication with Cumberland Gap, and he learned that Major-General John G. Foster was at Tazewell, under orders to relieve him of the command of the department. This was in apparent accord with the wish which Burnside had expressed, [Footnote: Ante, vol. i. pp. 527, 528.] but as action had been postponed it was reasonable to expect that further consultation would be had before he should be relieved, and that Grant's judgment would be asked in regard to it. After the controversies which followed the battle of Fredericksburg, Halleck was habitually unfriendly to Burnside, and we have seen how uniformly a wrong interpretation was given to the events of the current campaign. Foster's appointment to succeed Burnside was dated the 16th of November, [Footnote: Official Records, vol. xxxi. pt. iii. p. 166.] and he had been in Kentucky or near Cumberland Gap during the siege of Knoxville. The day the order was made relieving Burnside was that on which he was battling with Longstreet at Campbell's Station, holding him at bay in the slow retreat upon Knoxville, where he arrived on the 17th. On this morning Grant was writing him, "So far you are doing exactly what appears to me right," [Footnote: Id., p. 177.] and this was written after the receipt of Dana and Wilson's full dispatches of the 13th and 14th, as well as Burnside's of the 13th. [Footnote: Id., p. 138.] Yet so strangely was the same information misread by Halleck, that on the 16th he was telegraphing Grant that Burnside was hesitating whether to fight or retreat out of East Tennessee. "I fear he will not fight," he added, "although strongly urged to do so. Unless you can give him immediate assistance, he will surrender his position to the enemy." [Footnote: Id., p. 163. This dispatch of Halleck seems to have been called out by one of Dana to Stanton on the 14th in which he said, "Burnside has determined to retreat toward the Gaps." (Official Records, vol. xxxi. pt. i. p. 259.) Halleck failed to interpret this in connection with one of the 13th in which Dana had stated alternate lines of retreat, "if finally compelled," and Burnside's judgment in favor of the line of Cumberland Gap in such last resort rather than toward Kingston. (Ibid.) Dana had fully conveyed, however, Burnside's determination to hold Knoxville "as long as possible," and his reasons for making a stubborn fight there. By failing to keep this in mind, the Secretary and General-in-Chief became unnecessarily agitated, and forgot in their conduct what was due to Grant almost as much as what was due to Burnside.] On the next day Burnside entered Knoxville, where fortifications had been hurriedly built, and the siege began. The heroic defence of Knoxville lasted three weeks, and when Longstreet withdrew toward Virginia, the successful general learned that he had been removed from command at the very moment he was completing, with Grant's unqualified approval, the preparation for that stubborn resistance which saved East Tennessee and averted the "terrible misfortune" which Halleck feared. [Footnote: Id., pt. iii. p. 145.] The importance of holding East Tennessee, now that it had been liberated, was urged upon the War Department by Burnside from the beginning. He had pointed it out when ordered to abandon it and march to Rosecrans's assistance. [Footnote: Id., vol. xxx. pt. iii. p. 904.] So far from hesitating to fight Longstreet, Dana found him determined to "expose his whole force to capture rather than withdraw from the country." [Footnote:Id., vol. xxxi. pt. i. p. 260.] It was not till Mr. Dana's later dispatches were received that the misapprehensions were corrected at Washington. Then the story of the occupation and defence of East Tennessee was explained, and justice was done the wisdom of the general's course as well as his patriotic and unselfish spirit. A part of the trouble had been due to the fact that after Grant reached Nashville Burnside's correspondence was with him, and, in accord with military usage, he dropped direct correspondence with Washington, except when addressed from there.
It was too late, however, to undo what had been done. Foster was in Kentucky, carrying forward into East Tennessee such detachments as could be picked up. He reached Knoxville on the 10th of December, and the next day Burnside turned over the command to him, and started for Cincinnati by way of Jacksboro and Williamsburg. [Footnote: Official Records, vol. xxxi. pt. iii. pp. 372, 384.] The President was most hearty in his approval of Burnside's conduct when once he understood it, and insisted that after a brief rest he should again enter into active service. Congress passed strong resolutions of thanks to him and to his troops, [Footnote: Id., pt. i. p. 281.] and it began to be understood that the campaign had been a creditable one.