The 21st, with its brigade, pursued retreating Confederate forces, engaging them in skirmishes near Big Shanty. They drove a North Carolina regiment from their position, taking captives, and moved into position before Kennesaw Mountain. The regiment received severe bombardment during the Battle of Kennesaw Mountain, but held their ground until Sherman's flanking maneuver forced the enemy to abandon their position. After Kennesaw, Lt. Col. Hobart was assigned to command three regiments of the first Brigade, and Major Michael H. Fitch was assigned to replace him as commander of the 21st Regiment.