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.

In early 1862, the regiment's initial period of service expired, but many men continued to fight in different units.

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.

The Georgia elements of the regiment were redesignated the 122nd Infantry on 9 June 1924, and all World War I honors were retained by that organization.