Activated at Camp Elliott in September 1942, the 3rd Marine Division was formed using the 9th Marine Regiment as its nucleus. After training on Guadalcanal, the Division landed in Bougainville on 1 November 1943, where it continued to fight until the 9 January 1944. Its next action came during the battle to reclaim Guam, which had fallen to the Japanese within days of the attack on Pearl Harbor some three-and-a-half years earlier. Following the July 21, 1944 landing, the Division was responsible for killing some 5,000 Japanese troops, but at a loss of over 670 dead and more than 3600 wounded.
This battle served as a prelude to fighting on Iwo Jima, where two of the Division’s regiments—the 21st and the 9th—were reinforced by a battalion from the 3rd Marine Division and supported by artillery and tanks from the 12th Marine Regiment and the 3rd Tank Battalion. Between 20 February and 16 March 1944, the 3rd suffered over 1,130 killed in action and some 4400 wounded.
The Division did not see combat during the Korean War, but in March 1965 it became the first unit to send ground combat troops to Vietnam when the 3rd Regiment was deployed to defend the airfield at Da Nang. By the end of that year, all three of the Division’s regiments—the 3rd, 4th, and 9th—had been deployed there. Although the 3rd Marine Division was one of the first units to return stateside as a result of Vietnamization—the division left Vietnam in November 1969—it suffered nearly as many casualties as the 1st Marine Division, which stayed until April 1971.
Today, the “Fighting Third” is based at Camp Courtney in Okinawa and, like the 1st and 2nd Marine Divisions, is the ground component of a Marine Expeditionary Force. It comprises a Headquarters Battalion, three Marine Regiments (3rd, 4th, and 12th), the 3rd Reconnaissance Battalion, and a Combat Assault Battalion. The 3rd Marine Division’s patch is made in gold and scarlet, official Marine Corps colors, and features a shield with a caltrap—a device originally designed to impede enemy cavalry—in the center.