The 122nd Infantry Regiment traces lineage to the Gate City Guards in Atlanta. At the time, Atlanta was known as "The Gate City" of the South, because it was a major railroad terminus in the region. In 1857, the Gate City Guard was founded as a private militia company which comprised 100 men and officers. In the American Civil War, Georgia voted to secede and join the Confederate States of America and the Gate City Guard was the first to offer their service to the governor, Joseph E. Brown. Traveling to Macon, they joined the 1st Georgia Infantry Regiment. While in the regiment, they fought in the Western Virginia Campaign, particularly in the Battle of Laurel Hill. In early 1862, the regiment's initial period of service expired, but many men continued to fight in different units. The Gate City Guard was eventually reformed in 1877 after the war. In 1898, the Gate City Guard was formed into a part of the 5th Georgia Infantry for service in the Spanish–American War, but never saw combat. In 1916, the 5th Georgia was redesignated the 122nd Infantry Regiment and was sent to the Mexico–United States border to protect against raids from Pancho Villa. In 1917, the regiment was put into the 31st Infantry Division, the "Dixie Division," for service in World War I. It went overseas in September 1918. Upon arrival in France, the 31st was designated as a replacement division. The personnel of the 122nd Regiment were withdrawn and sent to other organizations as replacements for combat casualties. The 122nd was part of the Army of Occupation in Southern Germany at Koblenz, at Fort Ehrenbreitstein.