On this day in 1863, Union troops capture Lookout Mountain southwest of Chattanooga, Tennessee, as they begin to break the Confederate siege of the city. In the "battle above the clouds," the Yankees scaled the slopes of the mountain on the periphery of the Chattanooga lines.

For nearly two months following the Battle of Chickamauga, the Confederates, commanded by General Braxton Bragg, had pinned the Union army inside Chattanooga. They were not able to surround the city, though, and occupied Lookout Mountain and Missionary Ridge to the south and east of the city instead. In late October, arriving to take command, Union General Ulysses S. Grant immediately began to form an offensive. On October 27, Union troops attacked Brown's Ferry southwest of Chattanooga and opened the Tennessee River to boats that brought much needed supplies to the besieged Yankees.

On November 23, Grant began to attack the center of the lines around the city. Lookout Mountain lay on the Union's far right, and the action there commenced on November 24. Yankee General Joseph Hooker commanded this wing, and his men advanced toward the fog-covered peak. Hooker did not plan to attack the entire mountain that day, thinking the granite crags would be difficult to overcome. The fog masked the Union advance, however, and Hooker's men climbed relatively easily. The Confederates had overestimated the advantages offered by the mountain, and 1,200 Rebels faced nearly 12,000 attacking Yankees. Artillery proved of little use, as the hill was so steep that the attackers could not even be seen until they appeared near the summit. Bragg did not send reinforcements because the Union attack against the Confederate center was more threatening than the sideshow around Lookout Mountain. The Confederates abandoned the mountain by late afternoon. The next day, Union forces launched a devastating attack against Missionary Ridge and successfully broke the Confederate lines around Chattanooga.