"The men of the 100/442 took terrific casualties. They showed rare courage and tremendous fighting spirit ... everybody wanted them."
- General George C. Marshall

WWII

The vast majority of the volunteers came from Hawaii, but over 800 were recruited from the internment camps on the mainland. The 100th and the volunteers joined at Camp Shelby, Miss., and formed the 442nd, designed as a self-sufficient combat unit with its own artillery and logistics.

While the rest of the unit trained in Mississippi, the 100th departed to join the 34th Infantry Division in North Africa, which was preparing for the invasion of Italy. After joining the Italian Campaign at Salerno, the 100th participated in the terribly bloody fighting at Monte Cassino in early 1944, site of a famous Benedictine monastery that was destroyed by Allied bombing. The battalion took such heavy casualties that some war correspondents starting referring to them as the “Purple Heart Battalion.” By the time the battalion was pulled of the line, some of the platoons were down to less than 10 men. The 100th later received its first of four presidential unit citations.

During the period from Salarino to just after the taking of Rome in WWII, the 100th Bn served as the second battalion of the 133rd Infantry Regiment. 

References

100th Bn, 442nd RCT WWII History.pdf
Wikipedia: 100th Infantry Battalion (United States)
Wikipedia: 442nd Infantry Regiment (United States)

100th/442nd Infantry Claims to fame

- The 442nd Regimental Combat Team received 21 Medals of Honor.
- The 100th received four Presidential Unit Citations.

100th/442nd Infantry Social Media

- Facebook: 100th/442nd 70th Anniversary Tour of France-July 2014
- Facebook: "442nd" Independent film project
- Facebook: Bco/100Bn/442RCT Reenactment Group
- Facebook: 100th/442nd RCT Manga/Graphic Novel
- Facebook: 100th Infantry Battalion Veterans aka Club 100