It joined the United Nations troops on the front lines during the stalemate of the second half of the war, with constant, low-level fighting and trench warfare against the People's Volunteer Army of China that produced little gain for either side.

Over the course of its history, the 45th Infantry Division sustained over 25,000 battle casualties, and its men were awarded ten Medals of Honor, twelve campaign streamers, the Croix de Guerre and the Republic of Korea Presidential Unit Citation.

[4] On 19 October 1920, units of the Oklahoma National Guard were organized as part of the 45th Infantry Division, also manned with troops from Arizona, Colorado, and New Mexico.

[8] As a consequence of these militia roots, when the division was properly organized, many of its members were marksmen and outdoorsmen from the remote frontier regions of the Southwestern United States.

[1] In August 1940, the 45th Division again participated in the Third Army maneuvers, this time near the Kisatchie National Forest in Louisiana as part of the provisional VIII Corps.

[20] Still operating with outmoded equipment from World War I, the division did not perform well during these exercises, and was criticized by officers who considered it "feeble.

[24] The division, now commanded by Major General Troy H. Middleton, a Regular Army soldier and highly distinguished World War I veteran, moved to the Hampton Roads Port of Embarkation's Camp Patrick Henry to await combat loading on the transports.

As a result, the division was not sent into combat upon arrival and instead commenced training at Arzew, French Morocco,[28] in preparation for the invasion of Sicily.

Allied intelligence estimated that the island was defended by approximately 230,000 troops, the majority of which were drawn mostly from weak Italian formations and two German divisions which had been reconstituted after being destroyed earlier.

Against this, the Allies planned to land 180,000 troops,[29] including the 45th Infantry Division, which was assigned to Lieutenant General Omar Bradley's II Corps, part of the U.S.

[35] For most of the first two weeks while the division moved slowly north, it encountered only light resistance from Italian forces fighting delaying actions.

In company with the British 1st Infantry Division, they advanced north along the Anzio-Albano road and captured the Aprilia "factory", but encountered ingrained resistance from German armored units a few miles further on.

[47] For the next few months the 45th Infantry Division was mostly stuck in place, holding its ground during repeated German counterattacks, and subjected to bombardment from aircraft and artillery.

Lucas sent famed U.S. Army Ranger leader Colonel William Orlando Darby to assume command of the 157th Infantry, and the Germans were repulsed.

On 23 May, VI Corps, now commanded by Major General Lucian Truscott, went on the offensive, breaking out of the beachhead to the northeast, with the 45th Division forming the left half of the attack.

[51] The 45th, 36th, and 3rd Infantry Divisions were pulled from the line in Italy in preparation for Operation Dragoon (formerly Anvil), the invasion of southern France.

[52] The 45th Infantry Division participated in its fourth amphibious assault landing during Operation Dragoon on 15 August 1944, at St. Maxime, in Southern France.

[41] The 45th Infantry Division landed its 157th and 180th regimental combat teams and captured the heights of the Chaines de Mar before meeting with the 1st Special Service Force.

[51] The 45th moved north to the Sarreguemines area and smashed through the Siegfried Line, on 17 March taking Homburg on the 21st and crossing the Rhine between Worms and Hamm on the 26th.

[58] During the next month, the division remained in Munich and set up collection points and camps for the massive numbers of surrendering troops of the German armies.

In the first two cases, dubbed the Biscari massacre, occurred on 14 July 1943, American troops from C Company, 180th Infantry Regiment, were alleged to have shot 74 Italian and two German prisoners in Acate following the capture of an airfield in the area.

[61][62][63] In a third incident, the Army considered court-martialling several officers of the 157th Infantry Regiment under Lieutenant Colonel Felix L. Sparks after servicemen were accused of massacring German soldiers who were surrendering at the Dachau concentration camp in 1945.

[67] Confessed murderer Frank Sheeran later recalled his war service with the 45th as the time when he first developed a callousness to the taking of human life.

In later interviews with Charles Brandt, he divided such massacres into four categories: During World War II, the 45th Division fought in 511 days of combat.

Due to drastic reductions in U.S. military spending following the end of World War II, these divisions were equipped with worn-out or obsolete weaponry and suffered from a shortage of anti-armor weapons capable of penetrating the hulls of the North Korean T-34 tanks.

Later that month, it was given 4,006 new recruits for its three infantry regiments and artillery assets, and each unit created a 14-week training program to prepare these new soldiers for combat.

Before the establishment of the 45th Infantry Division (NGUS) on 15 September 1952, the returning Oklahoma guardsmen were either separated from the service if their Guard enlistments had expired, or remained in inactive reserve status.

[117] The ensuing Battle of Hill Eerie was one of a series of larger attacks by Chinese and North Korean forces which produced heavier fighting than the previous year had seen.

[120] The division briefly patrolled the Korean Demilitarized Zone following the signing of the armistice ending the war, but most of its men returned home and reverted to National Guard status on 30 April 1954.

[121] The division remained as a unit of the Oklahoma National Guard and participated in no major actions throughout the rest of the 1950s save regular weekend and summer training exercises.