At 6:00 a.m. on the 2nd of May 1864, the 55th Ohio, along with the rest of the 20th Corps, broke winter quarters in Lookout Valley, Tennessee and, along with the rest of Sherman's Army, began the campaign towards Atlanta, Georgia. On the 7th of May, the 55th Ohio was part of a diversionary move against Buzzard Roost Gap while Gen. Sherman sent General James B. McPherson and his Army of the Tennessee around the Confederates flank. The next day, Col. Wood's brigade made a reconnaissance into the gap. Companies B and G of the 55th Ohio were ordered to take the crest. "Promptly and steadily they climbed the side of the bluff in the face of continued fire from the enemy's skirmishers, drove them from the occupied crest." The 55th Ohio lost 2 men killed and 2 wounded in this fight. Discovering that the rebels had heavily fortified their position, the Union forces were ordered to withdraw by nightfall. On May 13, the 20th Corps began its march towards Resaca, Georgia. The next day, the 55th, along with the rest of its brigade was drawn up in line 600 yards from a chain of fortified hills occupied by the rebels. The 55th had no casualties this day.On the 14th of May, 1864, the entire 3rd Division of the 20th Corps was moved to the extreme right of the army to the Dalton-Resaca road. Wood's brigade was hurriedly ordered to attack the enemy line with Ward's brigade in tandem. An aide to Colonel Wood rode up to Colonel Charles Gambee of the 55th Ohio and gave him the orders to attack the enemy lines. Captain Hartwell Osborne of Company, 55th Ohio, would later write in the regimental history of the eerie scene to follow: "Colonel Gambee was a veteran of many battles. He had won his eagles by hard service, and had proved himself a very brave man, but when he received this order he turned pale, trembled in his saddle, and did not recover his composure for some moments. He was soon called upon to form line, and showed no further signs of emotion; but the writer was greatly moved by the incident, which afterwards seemed prophetic."
At 1:00 p.m., the brigade advanced. No sooner had they crested the hill in their front when the Johnny's began firing devastating volleys into their ranks. The Union troops charged forward into an unbelievable hail of fire from the enemy troops in their dug in positions. Major Rudolphus Robbins of the 55th was killed in this attack. Lieutenant P.C. Lathrop, Company A, wrote the following: "In our charge down the hill we reached a slight depression or ravine separating the higher from a much lower hill along the brow of which the Fifty-Fifth boys, all along the line, were lying flat upon their faces, but firing at every head that appeared above the enemy's breastworks, only about thirty rods away, the Johnnies returning the fire at a lively rate. . . . Just behind me, and to my right, Sat Colonel Gambee, behind a pile of rails. Having several times been solicited to do so, I arose and went and sat down beside the Colonel. It was only a few minutes afterwards that the Johnnies made a charge upon our line. We immediately jumped to our feet, and as the Colonel opened his lips to issue a command, a bullet struck him in the breast, and he fell backwards into my arms, dead - killed instantly . . . I laid him down carefully, and, taking his revolver from his belt, I ran forward to rejoin my company. Halting, I tried to shoot the Rebel Colonel, who came within a few feet before he was shot. But I could not make the revolver work. I threw it down in disgust, but afterwards picked it up, and I think it was sent home with the Colonel's other personal effects. I do not now recall that I saw the Colonel's body after I laid it down when he was killed." As the rebels began to withdraw, the 54th Virginia Infantry charged Wood's brigade and was captured to a man. That evening, Wood's brigade was relieved and posted on the Dalton Road. At midnight there was a burst of musketry and artillery fire but it quickly subsided. The next morning, the Confederate works were found abandoned except for the many dead and wounded. The 55th felt the loss of Colonel Gambee. Though a strict disciplinarian, he was well liked by the men in the ranks. Lt. Col. James Stevens assumed command of the regiment. The 55th Ohio suffered severely in this fight, losing 23 killed (including Colonel Gambee and Major Robbins) and 70 wounded. It never recovered from these losses and "never paraded with full ranks again".
From the 18th of May until about the 22nd, the 55th Ohio, with its brigade, made a series of marches towards the Georgia town of Cassville and then rested there for a couple of days before retaking the march southeast. On May 25th, Lt. Col. Stevens resigned his commission. Captain Edwin H. Powers of Co. K assumed command of the 55th Ohio.
Sources:
Trials and Triumphs: A Record of the Fifty-Fifth Ohio Volunteer Infantry by Hartwell Osborne, 1904, A.C. Clurg & Co., Chicago.