Having successfully lifted the Siege of Chattanooga, General Grant now resolved on a double envelopment of Bragg's army. Major General William T. Sherman was ordered to attack with 20,000 men from the north along Missionary Ridge, while Major General Joseph Hooker was directed to attack from the south along Lookout Mountain, overwhelm the Southern forces there, then continue on to cut off Bragg's retreat while Sherman and Thomas pummeled him from the north and west. The contest kicked off on the morning of November 24, as Hooker drove Confederate forces from Lookout Mountain in the so-called "Battle Above the Clouds," while Sherman crossed the Tennessee River and took up positions along what he thought was the far edge of Missionary Ridge—only to learn that he had occupied a nearby hill, called Billy Goat Hill, instead. The 33rd Alabama, entrenched atop the south end of Missionary Ridge near Bragg's headquarters, heard the sounds of battle on Lookout Mountain, but could not see the action due to a dense fog that had enveloped it.