The unit saw intense combat during the Battle of Iwo Jima, participated in occupation duty in Japan and was quickly decommissioned shortly after the war.

The regiment was finally deactivated on April 30, 1970, as the Marine Corps began to draw down its force structure at the conclusion of the Vietnam War.

[1] Training continued at Camp Pendleton through the summer of 1944 which culminated in simulated amphibious landings on San Clemente Island.

[4] While at Tarawa the Division continued to train and incorporate lessons learned from each new amphibious landing that took place in the Pacific.

Reconnaissance parties and forward observers for the regiment came ashore at Red Beach 2, 1500 yards north of Mount Suribachi in the 5th wave at 0922 on D-Day to scout out artillery positions before the battalions arrived.

[6] The 105mm howitzers from 3/13 were in direct support of the 28th Marine Regiment as it wheeled south on the morning of February 21 to secure Mount Suribachi.

[7][8] On the evening of February 28 at 0215 in the morning the 5th Marine Division ammunition dump was hit causing a massive explosion and subsequent fire.