From The California State Military Museum
World War II
In response to the war in Europe, the California's 40th Infantry Division was mobilized on 3 March 1941 and sent to Camp San Luis Obispo where it remained, except for divisional maneuvers at Fort Lewis, Washington, until the attack on Pearl Harbor. While most of the division was from California, some of the supporting artillery, quartermasters and medics were also from Nevada and Utah. Almost immediately, two elements were split off to serve as separate units.
The 40th Tank Company from Salinas was sent to the Philippine Islands in 1941 and became Company C, 194th Tank Battalion. That battalion, made up of National Guardsmen from California, Minnesota, and Missouri, along with the 26th Cavalry Regiment (Philippine Scouts) were the covering force during the retreat to the Bataan Peninsula. When Bataan fell, these brave Californians, along with other US Army, Philippine Scouts, and Philippine Commonwealth Army soldiers, were part of the Bataan Death March and the subsequent imprisonment and slavery.
The division's observation squadron, the 115th was sent to the newly formed Army Air Forces where the served throughout the war. The 115th was later to form the backbone of the California Air National Guard when the Air Force was formed in 1947.
Within 48 hours of the attack on Pearl Harbor, Camp San Luis Obispo was a ghost town as elements of the 40th Infantry Division took defensive and security positions over a 350,000 square mile area that stretched from Southern and Central California to Yuma, Arizona and Salt Lake City, Utah. They dug in and prepared for what was thought to be the inevitable Japanese invasion of the West Coast.
In February of 1942, the division was reorganized from the old four regiment "square" division to the three regiment "triangular" division. This resulted in the 184th Infantry Regiment being made excess. That regiment went on to do great things during the war as part of the 7th Infantry Division. Later in the war, the 159th was replaced by the 108th Infantry Regiment from New York. They, along with the 3d Infantry Regiment (The Old Guard), went on to reconstitute the badly mauled 106th Infantry Division during the Battle of the Bulge.
In April 1942, the division moved to Fort Lewis, Washington for further training and preparation for overseas service. And soon that day would come. On 25 July, the division received orders to move to the Port of Embarkation at Camp Stoneman, California. By 8 August, the men of the division boarded a troopship, just as the fathers did during the First World War. And just as there forefathers did, the soldiers of the 40th established the shipboard routine of fire drills, gunnery drills, and abandon ship drills.
In September 1942 the division arrived in Hawaii and moved to defensive positions in the outer islands. In July 1943, the division moved to positions on Oahu. In October, with the threat of a Japanese invasion passing, the 40th took up jungle and amphibious training in preparation of offensive operations.
During December, the division moved to Guadalcanal for further training and limited combat patrolling. While on the "canal", the division didn't battle the Japanese. They instead fought the island's muddy conditions, its swamps, and mosquito-borne malaria. The division, now part of the 1st Marine Amphibious Corps, then moved to Cape Gloucester on New Britain Island and relieved the 1st Marine Division on 23 April 1944. The 40th conducted combat operations until 27 November 1944, when it was relieved by the 5th Australian Division. The 40th then assembled at Borgen Bay the next day and departed New Britain on 9 December 1944 for the their next objective, The Philippines.
After brief stopovers on New Guinea and Manus Island, the 40th Infantry Division landed in the Lingayen area of Luzon at 09:36 hours on 9 January 1945. It was followed up with another landing at Bamban. While opposition during the first landing was light, Bamban was a different story. The division battled the main Japanese force in the Bamban Hills, Fort Stotsenburg and Clark Field, The Zambales Mountains, Snake Hill, Storm King Mountain, The Seven Hills, and the mountain known as the Top of the World. In the final phase the battles moved to Scobia Ridge, Hill 1700, and Williams Ridge. On 2 March, the division was relieved by the 43d Infantry Division.
The division left Luzon on 15 March 1945 and conducted unopposed landings on Paney Islands on the 18th. They conducted combat operations in those islands until the division next moved to Los Negros Island where it conducted multiple landings with little or no opposition. The division regrouped on 8 April for an attack on the Japanese forces in the Negritos-Patog area. Prior to that attack, the 503d Parachute Infantry Regiment was assigned to the division, replacing the 108th Infantry Regiment. The division attacked with all three regiments (The 160th and 185th Infantry, and the 503d) on 9 April and immediately ran into stiff resistance and counterattacks. To make matters worse, the weather turned bad. Torrential rainstorms made air support impossible. Hill 3155 switched hands between the 160th Infantry Regiment and the Japanese Army several times between 18 and 23 May. Organized resistance ceased on 31 May and the 40th moved to the Otag-Santa Barbara-Taguan area for rehabilitation and training. The division was in this area when the war ended.
But while the shooting had stopped, the 40th's mission didn't end just yet. On 22 September 1945 the division arrived in Korea at the port of Inchon to take up occupation duties in that country. They remained in Korea until March 1946 when it returned to Camp Stoneman on 6 April 1946 and was inactivated. When it was all over, the 40th added three more streamers for the divisional colors: BISMARCK ARCHIPELAGO, SOUTHERN PHILIPPINES, and LUZON.
To view the 1945 Order of Battle CLICK HERE