100th Infantry Battalion

Livorno, Italy 1944: 100th passes in review to receive the Presidential Unit Citation for outstanding action at Belvedere, Italy. (Photo: U.S. Army Signal Corps)

The 100th Infantry Battalion was formed after the attack on Pearl Harbor, during a period of turmoil and fear in the Territory of Hawaii. The 100th was made up almost entirely of Nisei, second generation Americans of Japanese Ancestry (AJAs), who had learned traditional Japanese values at home and American principles of democracy at school. Young Nisei men had demonstrated their willingness to serve their country well before the attack, comprising nearly half of the 298th and 299th Infantry Regiments of the Hawaii National Guard.

In May 1942, the War Department ordered the formation of the segregated Hawaiian Provisional Battalion by transferring Nisei from the 298th, 299th and several engineer battalions based at Schofield Barracks. A month later these 1,432 Nisei sailed from Honolulu for California to form the 100th Infantry Battalion (Separate) (which indicated it was unattached to a larger army unit). Reflecting on their local roots, the soldiers soon adopted the unit nickname “One Puka Puka.” After over a year of intense training at Camp McCoy, Wisconsin and Camp Shelby, Mississippi, the 100th had become one of the best prepared units in the Army and would live up to its motto to “Remember Pearl Harbor.”

100th IB Italy 1944

Italy 1944: Company D, 100th, on the move. (Photo: U.S. Army Signal Corps)


Italy 1943: Company B, 100th, moving into the line. (Photo: U.S. Army Signal Corps)

Landing first in North Africa in September 1943, and quickly moving to the southern tip of Italy, the unit fought valiantly in the Allied forces’ drive to Rome, the brutal battle of Monte Cassino, and the breakout from the Anzio beachhead. The battle for Monte Cassino marked the end of the original 100th Battalion — by February 1944, the 100th had suffered nearly 800 wounded and killed in action and was nicknamed “The Purple Heart Battalion.” Following Cassino, the 100th began receiving replacements from the 442nd Regimental Combat Team, which was still in training at Camp Shelby, MS. After the 442nd arrived on the Italian battlefield the 100th became part of the regiment in June 1944. The100th took the place of the 1st Battalion, which remained back at Camp Shelby training new Nisei soldiers to replace the valiant Nisei killed and wounded in battles to the end of the war.

For more information please visit the 100th Infantry Battalion Veterans Education Center.


Livorno, Italy 1944: Capt. Young Oak Kim, Lt Gen Mark Clark and Undersecretary of War, Robert Patterson, review an Honor Guard of the 100th. (Photo: U.S. Army Signal Corps)


Italy July 1944: Battle Streamers, awarded by a Presidential Unit Citation to the 100th. (Photo: U.S. Army Signal Corps)

Nisei Veterans Legacy