Battles for Chattanooga

Background

After Chickamauga the Army of the Cumberland fell back into Chattanooga, a rail junction on the Tennessee River, and by 22 September was entrenched in a tight arc around the town. Bragg chose to besiege rather than assault it. From Lookout Mountain and Missionary Ridge his batteries and sharpshooters closed the river, the railways and the roads south of it, leaving a supply route nearly 60 miles long over Walden's Ridge from Bridgeport. Autumn rains washed out the mountain roads, Wheeler's cavalry wrecked a train of 800 wagons on 1 October, and the horses and mules began to die.

Washington reacted fast. Hooker came west with two corps from the Army of the Potomac, Sherman marched from Vicksburg with the Army of the Tennessee, and on 17 October Grant was given the new Military Division of the Mississippi. Rosecrans was relieved and Thomas took the army; Grant reached Chattanooga on 23 October. Baldy Smith's plan to reopen the river was put in hand at once: before dawn on 27 October Hazen's brigade floated past Lookout Mountain on pontoons and seized Brown's Ferry, and Hooker's column linked up there on the afternoon of the 28th. Longstreet's night attack on Geary at Wauhatchie on 28–29 October failed, and the 'Cracker Line' was open.

Bragg, his army riven by feuds with its generals, then divided it. On 5 November Longstreet's corps left to attack Burnside at Knoxville, and on 22 November Bragg ordered Cleburne's and Buckner's divisions to follow. Grant, under pressure to relieve Burnside, planned for Sherman to cross the Tennessee and roll up the north end of Missionary Ridge while Thomas held the centre. Sherman's slow march, rain and a broken bridge at Brown's Ferry put the attack back from 21 November.

The armies

Grant had most of three armies. Thomas's Army of the Cumberland, the men beaten at Chickamauga, held the centre with Granger's IV and Palmer's XIV Corps. Sherman brought four divisions of the XV and XVII Corps from Vicksburg. Hooker had Howard's XI Corps and Geary's division of the XII from Virginia; on 24 November he fought with Geary, Cruft's division of the IV Corps and Osterhaus's of the XV, three divisions from three armies that, one man wrote, had never seen each other. The Official Records count 72,533 Union troops present for duty about Chattanooga; Livermore counts some 56,000 engaged.

Bragg had perhaps 44,000 to 49,000 men in two corps, Hardee's and Breckinridge's, spread along a line more than five miles long, from Tunnel Hill at the north end of Missionary Ridge, across the Chattanooga Valley to the bench of Lookout Mountain. Breckinridge had only about 16,000 men for the centre and right. His dispositions were poor. On the ridge the rifle pits at its foot were too long for the men in them, and the main works ran along the topographical crest, not the military crest, so that guns and riflemen could not cover the ravines below. On Lookout Mountain the bench where the defence had to be made was overlooked by Union guns at Moccasin Point, and the summit batteries could not depress far enough to reach it. Bragg had sent away most of his cavalry, and with it his eyes.

The battle

CDB90 records one engagement, number 201 (CHATTANOOGA), from 10:00 on 24 November to 18:00 on 25 November; the page includes Orchard Knob on the 23rd as the opening of the battle, as the NPS, ABT and most historians do. Times are approximate and sources differ by up to an hour.

23 November: Orchard Knob. Told by deserters that Bragg was falling back (the column seen was Buckner leaving), Grant had Thomas test the line. Wood's division, with Sheridan's on its right and Howard's corps on the left, formed in plain view outside the works, more than 20,000 men in parade-ground order. At about 13:30 to 14:00 some 14,000 went forward at the double against perhaps 600 Confederates, who fired a volley and ran. Orchard Knob, a hundred-foot knoll about a mile short of Missionary Ridge, became Grant's headquarters. Bragg recalled Cleburne from Chickamauga Station and moved Walker's division from Lookout Mountain to the north end of the ridge.

24 November: Lookout Mountain, the Battle Above the Clouds. With Osterhaus stranded in Lookout Valley, Grant let Hooker attack the mountain. Geary crossed Lookout Creek near Wauhatchie at about 08:00–08:30 and worked north along the slope beneath the cliffs, while Cruft and Osterhaus forced the creek lower down. Walthall's 1,500 Mississippians, outflanked and outnumbered, were driven around the point of the mountain to the Cravens farm, which Hooker held by about noon. Moore and Pettus came down from the summit and held a line beyond the house. By 14:00–15:00 fog had closed in, and both sides fired blindly into it until dark; Meigs, watching from below, coined the battle's name. Stevenson abandoned the mountain overnight under a lunar eclipse, and next morning the 8th Kentucky raised the flag on the summit.

At the other end of the line, Giles Smith's brigade crossed the Tennessee by pontoon boat before dawn on the 24th and Sherman's divisions were over by early afternoon. At about 16:00 he took what he thought was the north end of Missionary Ridge, only to find it was a separate hill, Billy Goat Hill, cut off from Tunnel Hill by a deep ravine. Cleburne's men had arrived there an hour or two earlier and were digging in. Sherman entrenched.

25 November: Tunnel Hill. Grant's plan now centred on Sherman. His attacks went in from soon after sunrise, but with only a few of his brigades at a time: Corse along the narrow crest from the north, Loomis across the fields to the west, then Buschbeck, Matthies and Raum up the western slope. Cleburne, reinforced from Stevenson's division, shifted men to each threat, and around 16:00 a counter-charge drove the Federals back down the hill. Sherman lost almost 2,000 men. To the south Hooker spent three hours bridging Chattanooga Creek and reached Rossville Gap only at about 15:30.

25 November: Missionary Ridge. With both flanks stalled, Grant ordered Thomas to take the rifle pits at the foot of the ridge to relieve Sherman. Granger's delays put the start back until the six signal guns fired at about 15:40. Baird, Wood, Sheridan and Johnson, about 23,000 men, overran the pits, then came under fire from the crest. Without waiting for orders, Willich's, Hazen's and Wagner's brigades and others went on up 200 to 400 feet of steep, stump-strewn slope; some officers believed the ridge itself was the objective. Grant, watching from Orchard Knob, asked who had ordered it; Thomas and Granger both disclaimed it. The line broke first near Bird's Mill Road around 16:30–17:00, and the Federals on the crest rolled it up north and south. Hooker's men, coming north from Rossville, trapped about 700 of Holtzclaw's brigade. Only Hardee's wing, with Cleburne as rearguard, got away in order.

Aftermath

The battle cost the Union about 5,800 men and the Confederates, by Bragg's count, 6,667, more than 4,100 of them missing, mostly prisoners; Grant claimed 6,142 prisoners and 40 guns were taken. Bragg's army crossed Chickamauga Creek in the night and fell back on Dalton, Georgia. Cleburne's rearguard stand at Ringgold Gap on 27 November checked Hooker's pursuit, and Grant, short of rations and told to relieve Burnside, called it off; Sherman marched for Knoxville, where Longstreet's assault on Fort Sanders had already failed on 29 November.

Bragg blamed Breckinridge and the army, and resigned his command on 1 December; Joseph E. Johnston took over on 27 December. The Union now held Chattanooga, the 'Gateway to the Lower South', which became the base for Sherman's 1864 Atlanta campaign, and Grant went east in March to command all the Union armies. When a chaplain asked whether the dead should be buried by state, Thomas is said to have replied: "Mix 'em up. I'm tired of States' rights."

The argument is over how the ridge fell. Hattaway and Jones called it "the war's most notable example of a frontal assault succeeding against intrenched defenders holding high ground". Cozzens stresses how far the order to stop at the rifle pits was misunderstood; Woodworth calls the ridge's strength mostly a bluff. Sherman's handling of Tunnel Hill is criticised by Eicher, while Liddell Hart argued he held back deliberately, hoping Bragg would attack him.

Wargaming it

Chattanooga is really three battles and a siege, which suits a campaign or a linked series better than one big table. Brigade level, one unit per brigade and turns of 30 minutes to an hour, will handle any day; the whole front from Lookout Mountain to Tunnel Hill is about eight miles, too wide for most tables at that scale. Regimental games suit Tunnel Hill, the bench of Lookout Mountain around the Cravens house, and a single division's climb up Missionary Ridge.

Terrain decides everything. Lookout Mountain needs a steep, wooded slope beneath impassable cliffs, a narrow bench and Union guns firing in from Moccasin Point, with fog that cuts visibility from the early afternoon. Missionary Ridge needs three lines: rifle pits at the foot, half-built works on the slope, and a crest line placed so that the defenders cannot see into the ravines. Tunnel Hill wants a narrow crest, a ravine and a railway tunnel, held by a small, well-led division against much larger numbers.

The decisions are Grant's and his subordinates'. Does Sherman feed in a few brigades or swing wide round Cleburne's flank? Does Hooker find the Chattanooga Creek bridge intact? Do Thomas's divisions stop at the rifle pits? A rule that lets assaulting troops pinned under fire go on without orders, or fall back, captures 25 November. On the Confederate side the what-ifs are Cleburne and Buckner never sent away, and the crest line dug on the military crest.

Maps and pictures