100th Infantry Battalion and 442nd Regimental Combat Team
The 100th Infantry Battalion fought in six major campaigns from its arrival in Italy in September 1943 until the end of World War II in Europe in May 1945.
100th Infantry Battalion (Separate)
Period: September 1943 – August 1944
Campaigns: Naples-Foggia Campaign (Italy); Anzio Campaign (Italy); Rome-Arno Campaign (Italy)
100th Battalion, 442nd Infantry Regiment
Period: August 1944 – May 1945
Campaigns: Rome-Arno Campaign (Italy); North Apennines Campaign (Italy); Rhineland Campaign (France); Po Valley Campaign (Italy)
Unit Overview:
100th Infantry Battalion (Separate). On June 5, 1942, the unit departed Honolulu Harbor in secrecy and was activated as the 100th Infantry Battalion (Separate) on June 12, 1942, upon arriving in Oakland, California. The 100th was then transferred to Camp McCoy, Wisconsin, and later to Camp Shelby, Mississippi, for training. On August 21, 1943, the 100th Infantry Battalion (Separate) deployed to Oran in North Africa, boarding the S.S. James Parker from Staten Island, New York, and arriving on September 2, 1943.
The 100th landed on the beaches of Salerno, Italy on September 22, 1943 with just over 1,300 men, becoming the first World War II unit of Americans of Japanese ancestry (AJA) to engage in combat in the European-African-Middle Eastern Theater. The battalion was attached to the 133rd Infantry Regiment of the 34th Infantry Division, commanded by Major General Charles W. Ryder. On September 26, the unit entered combat operations in pursuit of retreating German troops. On September 29, the 100th first engaged German forces, and during this battle, Sgt. Joseph Shigeo Takata (Co. B) became the first in the unit to be killed in action.
During the early battles in Italy, the fighting was slow and difficult, often taking place in difficult terrain where German forces had established strong defensive positions in the mountains, hills, and small towns. Allied soldiers had to move uphill toward enemy positions under heavy machine-gun and artillery fire, mines, and fortifications. In its first five months of combat including the Battle of Monte Cassino, the 100th suffered many casualties, meaning soldiers were killed, wounded, or could no longer fight. By late February 1944, the battalion’s strength dropped to about 460 effectives (soldiers who were still able to fight and perform their duties). Due to the extremely high casualty rate, war correspondents began calling the 100th “The Purple Heart Battalion,” referring to the Purple Heart medal given to soldiers wounded or killed in action by enemy forces.
Replacement soldiers were sent to reinforce the 100th Infantry Battalion (Separate) from the 442nd Regimental Combat Team (RCT), a segregated unit composed of Americans of Japanese ancestry (AJA). The 442nd was activated on February 1, 1943 with volunteer AJA men, and was training at Camp Shelby. These groups of replacements arrived in Italy to join the 100th in March and April 1944, and a third group arrived in May 1944.
On June 11, 1944, shortly after the 442nd RCT arrived as a unit in Italy, the 100th was attached to the 442nd Infantry Regiment, serving as its 1st Battalion. The original 1st Battalion, 442nd Infantry Regiment, depleted after sending many soldiers as replacements to the 100th earlier in 1944, remained at Camp Shelby. It served primarily as a training and replacement unit and was redesignated the 171st Infantry Battalion (Separate) on September 5, 1944.
100th Battalion, 442nd Infantry Regiment. On August 10, 1944, the 100th Infantry Battalion (Separate) was redesignated the 100th Battalion, 442nd Infantry. In recognition of its outstanding training and distinguished combat record in Italy before the arrival of the 442nd RCT, the Army allowed the battalion to retain its “100th” designation.
Campaigns:
Note: Campaigns are listed in the order of overall Allied operations, and not necessarily the sequence of the 100th Infantry Battalion’s participation.
- Naples-Foggia Campaign (Italy)
August 18, 1943 – January 21, 1944 (Air); September 9, 1943 – January 21, 1944 (Ground); from the Allied invasion of Italy to the battles along the Winter Line.
- 100th Infantry Battalion (Separate): September 22, 1943 – January 21, 1944Attached to the 34th Infantry Division, the 100th landed at Salerno and fought a series of battles pushing inland, crossing the Volturno River three times. Heavy fighting followed in actions near Alife, along the Rapido River, and in the hills around Pozzilli, where soldiers advanced across exposed terrain and often uphill toward German positions through rain, mud, mines, and artillery fire as they moved toward Monte Cassino.
② Anzio Campaign (Italy)
January 22, 1944 – May 24, 1944; the Allied amphibious landing and battles at Anzio.
- 100th Infantry Battalion (Separate): March 26, 1944 – May 24, 1944
③ Rome-Arno Campaign (Italy)
January 22, 1944 – September 9, 1944; from the Anzio landings to the Allied advance to the Gothic Line.
- 100th Infantry Battalion (Separate): January 22, 1944 – late March 1944 (Cassino) and late May 1944 – June 1944 (Anzio breakout; Lanuvio to Rome)
- 100th Infantry Battalion (Separate) / 100th Battalion, 442nd Infantry: June 11, 1944 – September 9, 1944By February 1944, casualties were so heavy the 100th was called “The Purple Heart Battalion.” Monte Cassino marked the end of the original 100th contingent, as replacements from the 442nd RCT began arriving in March 1944.
In late March 1944, the 100th Infantry Battalion (Separate) was transferred from the Cassino sector to the Anzio beachhead, where it fought from March to May 1944 during the Anzio Campaign while remaining part of the broader Rome–Arno Campaign. The unit arrived at the Anzio beachhead on March 26.
The beachhead formed a second front between the German Gustav Line and Rome. At the time, strong German resistance had created a stalemate, and the 100th carried out its orders to patrol its assigned sector, repel enemy infiltration, and gather intelligence on German movements. Success by Allied forces at Anzio, combined with a breakthrough at Monte Cassino, would open the way for the Allied advance on Rome. When the breakout from the beachhead began at the end of May, the 100th spearheaded the advance to capture Lanuvio, a major German stronghold guarding one of the main routes from Anzio toward Rome.
In early June, the 100th met up with the newly arrived 442nd RCT at Civitavecchia, and the 100th Infantry Battalion (Sep) was attached to the 442nd RCT, taking on the role of the 1st Battalion of the 442nd Infantry Regiment.
Near Belvedere, Maj. Gen. Charles Ryder, commanding the 34th Infantry Division, placed the 442nd RCT in the center of the divisional line for its first battle in Italy. On June 26, 1944, under regimental commander Col. Charles Pence, the 2nd and 3rd Battalions of the 442nd led the attack while the 100th remained in reserve. When heavy German shelling halted the advance, Col. Pence ordered the 100th to attack at noon. With little time for reconnaissance, Lt. Col. Gordon Singles and his officers quickly organized the assault that helped capture Belvedere and push German forces back toward Sassetta. For its actions at Belvedere and Sassetta, the 100th Infantry Battalion (Separate) was awarded its first Distinguished Unit Citation (later renamed the Presidential Unit Citation).
④ North Apennines Campaign (Italy)
September 10, 1944 – April 4, 1945; battles against the German Gothic Line in the Apennine Mountains to open the route into northern Italy.
- 100th/442nd: late March 1945 – April 4, 1945On March 23, 1945, the 100th Battalion departed Marseilles via LST (Landing Ship, Tank) convoy in secrecy, arriving at Leghorn (Livorno), Italy on March 25. General Mark Clark, commander of the U.S. 5th Army, petitioned Allied command for their return to Italy to help break the German Gothic Line guarding the entrance to the Po Valley. The 100th/442nd was to be used as a secret weapon. In Italy, the unit was assigned to the U.S. 5th Army and coordinated with elements of the segregated 92nd Infantry Division, made up mostly of African American soldiers.
⑤ Rhineland Campaign (France)
September 15, 1944 – March 21, 1945; Allied operations to clear German forces west of the Rhine and prepare for the invasion of Germany.
- 100th/442nd: October 1944 – March 1945
100th/442nd departed Naples, Italy on September 27, 1944 for Marseille, France, and the men were trucked to the Vosges Mountains in northeast France on October 9. On October 11, the 100th/442nd was attached to the 36th Division of the 7th Army, commanded by Major General John Dahlquist. The 100th/442nd then began a period of intense, nearly continuous combat in the Vosges Mountains. In the month of October 1944, with the battles to liberate the towns of Bruyères and Biffontaine, followed by the rescue the “Lost Battalion” (1st Battalion, 141st Infantry Regiment, 36th Infantry Division), the 100th/442nd reported over 800 casualties, including 117 KIA. The 100th Battalion is awarded a second Presidential Unit Citation for outstanding action during this period.
On November 10, 1944, the 100th Battalion left Bruyères for Nice, and carried out reconnaissance and security patrols in the Maritime Alps sector. The battalion joined the 442nd Infantry Regiment near Menton, France. The 100th/442nd then held defensive positions along the border through the winter of 1944–1945, a period the soldiers nicknamed the “Champagne Campaign.” In March 1945, the regiment was relieved by French troops and ordered back to Italy.
⑥ Po Valley Campaign (Italy)
April 5, 1945 – May 8, 1945; the final Allied spring offensive in Italy, beginning with the breakthrough of the German Gothic Line at Monte Folgorito and leading to the surrender of German forces.
- 100th/442nd: from April 5, 1945 – May 8, 1945.On April 5, 1945, the 100th/442nd launched a surprise attack on German positions, breaking through the Gothic Line guarding the entrance to the Po Valley — the last major objective in northern Italy still under German control. In a coordinated assault near Massa, both the 3rd Battalion and the 100th Battalion moved into position overnight in pitch-black darkness. The 3rd Battalion crossed steep, rugged, and treacherous mountain terrain to get behind German positions. At dawn, the 100th led a frontal assault against the formidable defensive line, seizing its objective in 32 minutes and breaching the Gothic Line after months of unsuccessful Allied attempts to break the line. Meanwhile, the 3rd Battalion launched a surprise attack against the enemy’s flank and rear, and the 100th/442nd collapsed the German defenses.
The 100th/442nd then seized Carrara and continued pursuing enemy forces north along the Ligurian coast. A special commando unit, Task Force Fukuda, led by Major Mitsuyoshi Fukuda of the 100th, captured Aulla on April 25, 1945. For its actions during the Gothic Line campaign, the 100th earned its third Presidential Unit Citation.
By May 2, 1945, German resistance in Italy had collapsed, and German forces were surrendering by units. Germany’s unconditional surrender of its armed forces on May 8, 1945, marked the official end of World War II in Europe.
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※ Additional Combat Participation by elements of the 442nd RCT:
Southern France Campaign (France)
August 15, 1944 – September 14, 1944; the Allied landings in Southern France (Operation Dragoon).
- Anti-Tank Company, 442nd RCT: Detached from the 442nd in mid July 1944 and temporarily placed under the command of the 1st Airborne Task Force for the invasion of southern France. During the landings on August 15, 1944, it supported airborne units, including the 517th Parachute Infantry Regiment, and helped provide anti-tank and heavy weapons support in the early stages of the campaign before rejoining the 442nd RCT later in 1944.
Central Europe Campaign (France / Germany)
March 22, 1945 – May 11, 1945; the Allied advance into Germany.
- 522nd Field Artillery Battalion (FAB), 442nd RCT: Detached from the 442nd, the 522nd FAB left the Maritime Alps in mid-March 1945 and moved north through France into Germany, where it provided artillery support to several U.S. divisions, including the 63rd, 45th, and 44th Infantry Divisions. The battalion also helped liberate prisoners from Dachau concentration camp sub-camps as the war drew to a close.
Asiatic-Pacific Campaign (Hawaiʻi)
December 7, 1941, and March 2, 1946; the series of military operations conducted by U.S. forces in the Pacific Theater during World War II against Japan and its allies.
- Many of the original soldiers of the 100th Infantry Battalion (Separate) served in Hawai‘i with the federalized Hawaii National Guard under U.S. Army command, participating in the islands’ defense during and immediately after the Japanese attack on Pearl Harbor. Although no official campaign streamer was issued for this service, eligible soldiers were authorized the Asiatic-Pacific Campaign Medal in recognition of their active wartime service in the Pacific Theater.
Naples-Foggia Sept. 22, 1943 – Feb. 11, 1944: Attached to 34th Division, 100th lands at Salerno and fights a series of battles as it pushes inland, crossing Volturno River three times. Toughest battle is at Mount Cassino. It takes Allied forces four major assaults and four months to take Cassino. By Feb 1944, 100th has suffered so many casualties, it is called “the Purple Heart Battalion.” Cassino marks end of original contingent of 100th. Only 520 out of 1300 who arrived in Italy are still fit for combat. 
Anzio Mar 26 – June 2, 1944: 100th lands at Anzio, participates in breakout from beachhead, spearheads drive and capture of Lanuvio, last major German stronghold on road to Rome. Following week, 100th meets up with newly arrived 442nd RCT at Civitavecchia, Italy. 
Rome-Arno River June 21 – Sept 4, 1944: First combat experience for 2nd and 3rd Battalions of 442nd. 100th initially kept in reserve, but sent into battle when the two battalions aren’t making progress. In three hours 100th captures critical town of Belvedere. 100th earns first Presidential Unit Citation. 
Northern Apennines Sept 10, 1944 – April 1945: 100th assigned to IV Corps, crosses Arno River near Pisa. 442nd assigned to II Corps, crosses river near Florence. As they start to probe German defense – the Gothic Line – both units are pulled out, sent to France. In March 1945, 100th/442nd sent back to help break Gothic Line. 
Rhineland Sept 29, 1944 – Mar 21, 1945: 100th/442nd engage in heavy fighting in Vosges Mts near German border, liberating towns of Bruyeres and Biffontaine and rescuing the “Lost Battalion.” 100th/442nd sustains more than 800 casualties. 100th is awarded second Presidential Unit Citation for outstanding action during this period. 
Po Valley April 5 – May 2, 1945: 100th/442nd makes a surprise attack on German mountainside positions, breaking through Gothic Line. Special commando unit is formed, Task Force Fukuda, led by Major Mits Fukuda of 100th. Takes Aulla from fleeing Germans on Apr 25. 100th earns third Presidential Unit Citation for its part in Gothic Line campaign.