The 13th Marine Regiment was an artillery regiment of the United States Marine Corps. The regiment was activated for service three times during the 20th century when the Marine Corps expanded to meet war time requirements. Originally activated as an infantry regiment during World War I, the unit arrived in France before the war ended but did not participate in combat operations. It was reactivated for service in World War II as the artillery regiment for the 5th Marine Division. 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 last activated during the Vietnam War to again provide fire support for 5th Marine Division regiments supporting operations in South Vietnam. 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.

The 5th Marine Division was a United States Marine Corps ground combat division which was activated on 11 November 1943 at Camp Pendleton, California during World War II. The 5th Division saw its first combat action during the Battle of Iwo Jima in 1945 where it sustained the highest number of casualties of the three Marine divisions of the V Amphibious Corps. The 5th Division was to be part of the planned invasion of the Japan homeland before Japan surrendered. Assault troops of the 5th Division were included in the Presidential Unit Citation awarded to the V Amphibious Corps for extraordinary heroism on Iwo Jima from 19 to 28 February 1945. The 5th Division was deactivated on 5 February 1946.