Lookout Mountain was one engagement in the Chattanooga battles between Maj. Gen. Ulysses S. Grant's Military Division of the Mississippi and the Confederate Army of Tennessee, commanded by Gen. Braxton Bragg.

It drove in the Confederate left flank and allowed Hooker's men to assist in the Battle of Missionary Ridge the following day, which routed Bragg's army, lifting the siege of Union forces in Chattanooga, and opening the gateway into the Deep South.

After their disastrous defeat at the Battle of Chickamauga, the 40,000 men of the Union Army of the Cumberland under Maj. Gen. William Rosecrans retreated to Chattanooga, Tennessee.

On October 17, Maj. Gen. Ulysses S. Grant received command of the Western armies, designated the Military Division of the Mississippi.

Jackson later wrote about the dissatisfaction of the commanders assigned to this area, "Indeed, it was agreed on all hands that the position was one extremely difficult to defense against a strong force of the enemy advancing under cover of a heavy fire.

Grant, Sherman, and Thomas planned a double envelopment of Bragg's force, with the main attack by Sherman against the northern end of Missionary Ridge, supported by Thomas in the center and by Hooker, who would capture Lookout Mountain and then move across the Chattanooga Valley to Rossville, Georgia, and cut off the Confederate retreat route to the south.

[13] Surprised by Thomas's move against Orchard Knob on November 23, and realizing that his center might be more vulnerable than he had thought, Bragg quickly readjusted his strategy.

After receiving assurances from Sherman that he could proceed with three divisions, Grant decided to revive the previously rejected plan for an attack on Lookout Mountain and reassigned Osterhaus to Hooker's command.

Acknowledging that this was too large a force for a simple diversion, "Grant finally acceded to Thomas's persistent demand that a more serious effort be made."

Hooker ordered an artillery bombardment to saturate the Confederate line of retreat, but the effect was minimized because of poor visibility and the fact that the two forces were almost on top of each other.

It was covered with an untouched forest growth, seamed with the deep ravines, and obstructed with rocks of all sizes which had fallen from the frowning wall on our right.

The ground passed over by our left was not quite so rough; but, taking the entire stretch of the mountain side traversed by our force ... it was undoubtedly the roughest battle field of the war.

[24] As Geary's men appeared below the point around noon, Candy's brigade advanced across the lower elevations of the mountain, clearing the enemy from the east bank of Lookout Creek.

These movements isolated part of Walthall's Brigade and the entire 34th Mississippi was forced to surrender, along with 200 men from Moore's picket line.

[27]When Stevenson heard the fighting between Walthall and Geary, he ordered Pettus to take three regiments from the summit to assist Jackson.

By this time, Moore's Alabamians were moving up amidst Walthall's retreating men, and they fired on Ireland's New Yorkers from 100 yards.

Hooker was concerned that his lines were becoming intermingled and confused by the fog and the rugged ground and they were tempting defeat if the Confederates brought up reinforcements in the right place.

"[29] Moore's brigade was able to escape in the fog and Walthall had adequate time to form a rough defensive line 3–400 yards south of the Cravens house.

By this time Pettus's brigade of three Alabama regiments had descended from the summit and came to Walthall's assistance after 2 p.m.[30] Hooker sent to Grant alternating messages of panic and bluster.

For hours through the afternoon and into the night, the six Alabama regiments under Pettus and Moore fought sporadically with the Union troops through dense fog, neither side able to see more than a few dozen yards ahead nor make any progress in either direction.

[34] That night Bragg, stunned by the defeat on Lookout Mountain, asked his two corps commanders whether to retreat from Chattanooga or to stand and fight.

[36] On November 25, Hooker's men encountered difficulty rebuilding the burned bridges over Chattanooga Creek and were delayed in their movement toward the left flank of Bragg's remaining forces on Missionary Ridge.

Hooker faced his three divisions to the north and drove into Bragg's flank, furthering the disruption of the Confederate line, sending the Army of Tennessee into full retreat.

Hooker continued his role in the campaign with his unsuccessful pursuit of the Confederates that was beaten back at the Battle of Ringgold Gap.

[37] Casualties for the Battle of Lookout Mountain were relatively light by the standards of the Civil War: 671 Union, 1,251 Confederate (including 1,064 captured or missing).

[6] Sylvanus Cadwallader, a war reporter accompanying Grant's army, wrote that it was more like a "magnificent skirmish", than a major battle.

"[39] Nevertheless, the action was important in assuring control of the Tennessee River and the railroad into Chattanooga and endangering the entire Confederate line on Missionary Ridge.

Gen. Montgomery C. Meigs, quartermaster general of the Union Army, observing the fog-shrouded action from Orchard Knob, was the first writer to name it the "Battle Above the Clouds".