"With the outbreak of World War I, troops of the National Guard were formed into the units which exist today, with the Colorado Guard forming the 157th Infantry Regiment, the Arizona Guard forming the 158th Infantry Regiment, and the New Mexico Guard forming the 120th Engineer Regiment. These units were attached to the 40th Infantry Division and deployed to France where they were used as "depot" forces to provide replacements for front-line units. They returned home at the end of the war. The Oklahoma Guard units that would later become the 179th Infantry Regiment and 180th Infantry Regiment were assigned to the 36th Infantry Division and would earn a combat participation credit during the Meuse-Argonne Campaign (26 September – 11 November 1918) in France as the 142nd Infantry."
The 45th Infantry Division itself was created in 1920, largely of the Oklahoma Nation Guard. It was initially composed of the 157th, 158th, 179th, and 180th Infantry Divisions, and saw little action in the interwar years. In September 1941 it was federalized for service, alongside several other divisions. The Thunderbirds would go under harsh training for the next year, its men immediately began basic combat training at Fort Sill, Oklahoma. Throughout 1942, it continued this training at Camp Barkeley, Texas, before moving to Fort Devens, Massachusetts, to undergo amphibious assault training in preparation for an invasion of Italy. It then moved to Pine Camp, New York briefly for winter warfare training, but was hampered by continuously poor weather. In January 1943 it moved to Fort Pickett, Virginia, for its final training. The division moved to the Hampton Roads Port of Embarkation embarkation's Camp Patrick Henry to await combat loading on the transports. The 158th Regiment (Arizona's National Guard) was dropped from the division soon after activation. The "Bushmasters" would be sent to Panama for training, and deployed in the Pacific Theatre.
The 45th Infantry Division itself was created in 1920, largely of the Oklahoma Nation Guard. It was initially composed of the 157th, 158th, 179th, and 180th Infantry Divisions, and saw little action in the interwar years. In September 1941 it was federalized for service, alongside several other divisions. The Thunderbirds would go under harsh training for the next year, its men immediately began basic combat training at Fort Sill, Oklahoma. Throughout 1942, it continued this training at Camp Barkeley, Texas, before moving to Fort Devens, Massachusetts, to undergo amphibious assault training in preparation for an invasion of Italy. It then moved to Pine Camp, New York briefly for winter warfare training, but was hampered by continuously poor weather. In January 1943 it moved to Fort Pickett, Virginia, for its final training. The division moved to the Hampton Roads Port of Embarkation embarkation's Camp Patrick Henry to await combat loading on the transports. The 158th Regiment (Arizona's National Guard) was dropped from the division soon after activation. The "Bushmasters" would be sent to Panama for training, and deployed in the Pacific Theatre.
Sicily
The division sailed from the Hampton Roads Port of Embarkation for the Mediterranean region on 8 June 1943. By the time the 45th Division landed in North Africa on 22 June 1943, the Allies had largely secured the African theater. As a result the division was not sent into combat upon arrival and instead commenced training at Arzew, French Morocco, 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, including the 45th Division, which was assigned to II Corps of the Seventh United States Army for the operation.
The division was subsequently assigned a lead role in the amphibious assault on Sicily, coming ashore on 10 July. Landing near Scoglitti, the southernmost U.S. objective on the island, the division advanced north on the U.S. force's eastern flank. After initially encountering resistance from armor of the German Herman Goering Division, the division advanced, supported by paratroopers of the 82nd Airborne Division who landed inland on 11 July. The 82nd paratroopers, conducting their first combat jump of the war, then set up to protect the 45th's flank against German counterattack, but without weapons to counter heavy armor, the paratroopers had to rely on support from U.S. armored units to repulse the German Tiger I tanks. For most of the first two weeks while the division moved slowly north, it encountered only light resistance from Italian forces fighting delaying actions. Italian and German forces resisted fiercely at Motta Hill on 26 July, however, and for four days the 45th Infantry Division was held up there. On August 1, the division was withdrawn from the front line for rest and rear-guard patrol duty, after which the division was assigned to VI Corps of the Fifth United States Army, in preparation for the invasion of mainland Italy.
The division sailed from the Hampton Roads Port of Embarkation for the Mediterranean region on 8 June 1943. By the time the 45th Division landed in North Africa on 22 June 1943, the Allies had largely secured the African theater. As a result the division was not sent into combat upon arrival and instead commenced training at Arzew, French Morocco, 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, including the 45th Division, which was assigned to II Corps of the Seventh United States Army for the operation.
The division was subsequently assigned a lead role in the amphibious assault on Sicily, coming ashore on 10 July. Landing near Scoglitti, the southernmost U.S. objective on the island, the division advanced north on the U.S. force's eastern flank. After initially encountering resistance from armor of the German Herman Goering Division, the division advanced, supported by paratroopers of the 82nd Airborne Division who landed inland on 11 July. The 82nd paratroopers, conducting their first combat jump of the war, then set up to protect the 45th's flank against German counterattack, but without weapons to counter heavy armor, the paratroopers had to rely on support from U.S. armored units to repulse the German Tiger I tanks. For most of the first two weeks while the division moved slowly north, it encountered only light resistance from Italian forces fighting delaying actions. Italian and German forces resisted fiercely at Motta Hill on 26 July, however, and for four days the 45th Infantry Division was held up there. On August 1, the division was withdrawn from the front line for rest and rear-guard patrol duty, after which the division was assigned to VI Corps of the Fifth United States Army, in preparation for the invasion of mainland Italy.
Italy
On 3 September, Italy surrendered to the Allied powers. Hoping to occupy as much of the country as possible before the German army could react, the Fifth Army prepared to attack Salerno. On 10 September 1943, the division conducted its second landing at Agropoli and Paestum with the 36th Infantry Division, on the southernmost beaches of the attack. Opposing them were elements of the German 29th Panzergrenadier Division and XVI Panzer Corps. Against stiff resistance, the 45th pushed to the Calore River after a week of heavy fighting. The Fifth Army was battered and pushed back by German forces until 20 September, when American forces were finally able to break out and establish a more secure beachhead. On 3 November it crossed the Volturno River and took Venafro. The division had great difficulty moving across the rivers and through the mountainous terrain, and the advance was slow. After linking up with the British Eighth Army, which had advanced from the south, the combined force, under the Fifteenth Army Group, was stalled when it reached the Gustav Line. Until 9 January 1944, the division inched forward into the mountains reaching St. Elia, north of Cassino, before moving to a rest area.
Allied forces conducted a frontal assault on the Gustav Line stronghold at Monte Cassino, and VI Corps was assigned Operation Shingle, detached from the Army Group to land behind enemy lines at Anzio on 22 January. Landing on schedule, VI Corps surprised the German forces, but Major General John P. Lucas's decision to consolidate the beachhead instead of attacking gave the Germans time to bring the LXXVI Panzer Corps forward to oppose the landings. On 30 January 1944, when VI Corps moved out, it encountered heavy resistance from German armored units which inflicted heavy casualties.The fight became a war of attrition, and for the next four months the division stood its ground during repeated German counterattacks.[39] The 45th Infantry Division was mostly stuck in place as the Pimlott Line was subjected to bombardment from aircraft and artillery fire. It was May before the Germans, reeling from heavy bombing and repeated attacks from the Fifteenth Army Group, began to withdraw. On 23 May the division went on the offensive, crossing the Tiber River by 4 June and, in the process, outflanking Rome. VI Corps linked up with the rest of the Fifth Army by 25 May, and as the division crossed the river, the Fifth Army entered and captured Rome. As a result, the 45th Infantry was the first military unit to enter the Vatican. On 16 June, it withdrew for rest in preparation for another assault.[39] During this time, VI Corps was attached to the Seventh United States Army, Sixth United States Army Group, part of a buildup in preparation for an invasion of mainland Europe in southern France, called Operation Anvil, which was originally planned to coincide with Operation Overlord in the north.The 45th, 36th and 3rd Infantry Divisions were pulled from the line in Italy to conduct Operation Anvil, but the attack was delayed until August because of a shortage of landing craft.
On 3 September, Italy surrendered to the Allied powers. Hoping to occupy as much of the country as possible before the German army could react, the Fifth Army prepared to attack Salerno. On 10 September 1943, the division conducted its second landing at Agropoli and Paestum with the 36th Infantry Division, on the southernmost beaches of the attack. Opposing them were elements of the German 29th Panzergrenadier Division and XVI Panzer Corps. Against stiff resistance, the 45th pushed to the Calore River after a week of heavy fighting. The Fifth Army was battered and pushed back by German forces until 20 September, when American forces were finally able to break out and establish a more secure beachhead. On 3 November it crossed the Volturno River and took Venafro. The division had great difficulty moving across the rivers and through the mountainous terrain, and the advance was slow. After linking up with the British Eighth Army, which had advanced from the south, the combined force, under the Fifteenth Army Group, was stalled when it reached the Gustav Line. Until 9 January 1944, the division inched forward into the mountains reaching St. Elia, north of Cassino, before moving to a rest area.
Allied forces conducted a frontal assault on the Gustav Line stronghold at Monte Cassino, and VI Corps was assigned Operation Shingle, detached from the Army Group to land behind enemy lines at Anzio on 22 January. Landing on schedule, VI Corps surprised the German forces, but Major General John P. Lucas's decision to consolidate the beachhead instead of attacking gave the Germans time to bring the LXXVI Panzer Corps forward to oppose the landings. On 30 January 1944, when VI Corps moved out, it encountered heavy resistance from German armored units which inflicted heavy casualties.The fight became a war of attrition, and for the next four months the division stood its ground during repeated German counterattacks.[39] The 45th Infantry Division was mostly stuck in place as the Pimlott Line was subjected to bombardment from aircraft and artillery fire. It was May before the Germans, reeling from heavy bombing and repeated attacks from the Fifteenth Army Group, began to withdraw. On 23 May the division went on the offensive, crossing the Tiber River by 4 June and, in the process, outflanking Rome. VI Corps linked up with the rest of the Fifth Army by 25 May, and as the division crossed the river, the Fifth Army entered and captured Rome. As a result, the 45th Infantry was the first military unit to enter the Vatican. On 16 June, it withdrew for rest in preparation for another assault.[39] During this time, VI Corps was attached to the Seventh United States Army, Sixth United States Army Group, part of a buildup in preparation for an invasion of mainland Europe in southern France, called Operation Anvil, which was originally planned to coincide with Operation Overlord in the north.The 45th, 36th and 3rd Infantry Divisions were pulled from the line in Italy to conduct Operation Anvil, but the attack was delayed until August because of a shortage of landing craft.
France and Germany
The 45th Infantry Division participated in its fourth assault landing during Operation Dragoon on 15 August 1944, at St. Maxime, in Southern France.The division landed its 157th and 180th regimental combat teams and captured the heights of the Chaines de Mar before meeting the 1st Special Service Force. The German Army, reeling from the Battle of Normandy, pulled back after a short fight, part of an overall German withdrawal to the east following the landings. Soldiers of the 45th Infantry Division engaged the dispersed forces of German Army Group G, suffering very few casualties. They then took the strongly defended city of Epinal on 24 September.[39] The division was then reassigned to V Corps for its next advance. On 30 September the division crossed the Moselle River and entered the western foothills of the Vosges, taking Rambervillers. It would remain in the area for a month waiting for other units to catch up before crossing the Mortagne River on 23 October. After the crossing was complete, the division was relieved from V Corps and assigned to XV Corps.[48] The division was allowed a one-month rest, resuming its advance on 25 November, attacking the forts north of Mutzig. These forts had been designed by Kaiser Wilhelm II in 1893 to block access to the plain of Alsace. The 45th Division next crossed the Zintzel River before pushing through the Maginot defenses. During this time much of the division's artillery assets were attached to the 44th Infantry Division to provide additional support. The 45th Infantry Division was reassigned to VI Corps on New Year's Day. From 2 January 1945, the division fought defensively along the German border, withdrawing to the Moder River. On 11 January the 157th began engagement in the devastating battle of Reipertswiller. Several companies were cut off and surrounded by SS troops, and casualties were extremely high. The soldiers trapped on the hills continued to resist small German holding attacks and endured heavy shelling. The supply of ammunition was rapidly dwindling, especially in K, I, and G Companies. The toll of dead and wounded mounted. Medical supplies were exhausted and many of the men had not had food for two days. In the end, by January 20th, the 157th was nearly completely destroyed. The division was pulled off the line to rest and regroup, as well as train the new flood of green replacements. Soon 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. The advance continued, with Aschaffenburg falling on 3 April, and Nuremberg on the 20th. The division crossed the Danube River on 27 April, and liberated 32,000 captives of the Dachau concentration camp on 29 April 1945. The division captured Munich during the next two days, occupying the city until V-E Day and the surrender of Germany. 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. The number of POWs taken by the 45th Division during its almost two years of fighting totalled 124,840 men. The division was then slated to move to the Pacific theater of operations to participate in the invasion of mainland Japan on the island of Honshu, but these plans were scrubbed before the division could depart after the surrender of Japan, on V-J Day.
The 45th Infantry Division participated in its fourth assault landing during Operation Dragoon on 15 August 1944, at St. Maxime, in Southern France.The division landed its 157th and 180th regimental combat teams and captured the heights of the Chaines de Mar before meeting the 1st Special Service Force. The German Army, reeling from the Battle of Normandy, pulled back after a short fight, part of an overall German withdrawal to the east following the landings. Soldiers of the 45th Infantry Division engaged the dispersed forces of German Army Group G, suffering very few casualties. They then took the strongly defended city of Epinal on 24 September.[39] The division was then reassigned to V Corps for its next advance. On 30 September the division crossed the Moselle River and entered the western foothills of the Vosges, taking Rambervillers. It would remain in the area for a month waiting for other units to catch up before crossing the Mortagne River on 23 October. After the crossing was complete, the division was relieved from V Corps and assigned to XV Corps.[48] The division was allowed a one-month rest, resuming its advance on 25 November, attacking the forts north of Mutzig. These forts had been designed by Kaiser Wilhelm II in 1893 to block access to the plain of Alsace. The 45th Division next crossed the Zintzel River before pushing through the Maginot defenses. During this time much of the division's artillery assets were attached to the 44th Infantry Division to provide additional support. The 45th Infantry Division was reassigned to VI Corps on New Year's Day. From 2 January 1945, the division fought defensively along the German border, withdrawing to the Moder River. On 11 January the 157th began engagement in the devastating battle of Reipertswiller. Several companies were cut off and surrounded by SS troops, and casualties were extremely high. The soldiers trapped on the hills continued to resist small German holding attacks and endured heavy shelling. The supply of ammunition was rapidly dwindling, especially in K, I, and G Companies. The toll of dead and wounded mounted. Medical supplies were exhausted and many of the men had not had food for two days. In the end, by January 20th, the 157th was nearly completely destroyed. The division was pulled off the line to rest and regroup, as well as train the new flood of green replacements. Soon 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. The advance continued, with Aschaffenburg falling on 3 April, and Nuremberg on the 20th. The division crossed the Danube River on 27 April, and liberated 32,000 captives of the Dachau concentration camp on 29 April 1945. The division captured Munich during the next two days, occupying the city until V-E Day and the surrender of Germany. 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. The number of POWs taken by the 45th Division during its almost two years of fighting totalled 124,840 men. The division was then slated to move to the Pacific theater of operations to participate in the invasion of mainland Japan on the island of Honshu, but these plans were scrubbed before the division could depart after the surrender of Japan, on V-J Day.