The XII Corps was transferred west to join the besieged Union army at Chattanooga. Geary's son Edward died in his arms at the Battle of Wauhatchie, enraging him sufficiently to prevail in a battle in which his division was greatly outnumbered. He distinguished himself in command during the Battle of Lookout Mountain, the entire Atlanta Campaign, Sherman's March to the Sea, and the Carolinas Campaign. He oversaw the surrender of Savannah, Georgia, and briefly served as the city's military governor, where he was breveted to major general.