At Utoy Creek, Georgia, on 5 August 1864 as part of Johnsons 1st Division, XIV Army Corps under MG John M Palmer, the Regular Brigade" that included the 18th Infantry was cited for making a crossing of North Utoy Creek under fire, assaulting and driving Armstrong's Confederate Cavalry Brigade, dismounted from their position at Peyton Road.

It then conducted a feint assault on 6 August 1864 to support XXIII Corps' attack at Utoy Creek, and participated in the three-week siege of Atlanta along the high ground east of Utoy Creek in southwest Atlanta, near Willis Mill and Adams Park (near current Fort McPherson).

[3] The 18th Infantry arrived at the port of New York on 3 September 1919 on the troopship USS Mobile, and was transferred to Camp Merritt, New Jersey, where emergency period personnel were discharged from the service.

Elements of the regiment served as honor guard for Marshal Henri Petain during his visit to New York City on 24 October 1931.

The cash incentive scheme comes as some top officers are questioning whether the practice of keeping their troops highly visible in Iraq is doing more harm than good.On 9 May 2010, a detachment led by Captain Matthew Strand from the 2nd Battalion, 18th Infantry Regiment represented the United States in Russia's Victory Day parade across Red Square at the request of Russian Minister of Defence Anatoly Serdyukov in a letter to U.S. Secretary of Defense Robert Gates.

[citation needed] A member of the contingent from Kemah, Texas, Russian-born 1st Lieutenant Ilya Ivanov, is a descendant of Major Alexander Peteryaev, a platoon leader in the Soviet Red Army.

[12][13][14] The Head of the Military University of the Russian Ministry of Defense, Colonel General Valery Marchenkov later awarded to soldiers for their participation in the parade.

[15] [15] Assigned to the 1st Division XIV Army Corps under Major General George H. Thomas, participated at the Battle of Chickamauga, GA as part of the Third (Regular) Brigade and was instrumental in preventing the destruction of the Union Army under Major General William Rosecrans at Chickamauga, GA Sep 1863.

Involved in cutting the rail lines south of Atlanta at Rough and Ready Station (Forest Park GA 30 Aug 1864).

The unit crest shows the symbol of the XIV Corps, the Acorn, adopted by Gen. George H. Thomas, "The Rock of Chickamauga."