40th Infantry Brigade Combat Team ( United States ) The 40th Infantry Brigade Combat Team was an infantry brigade of the United States Army National Guard in the state of California . Unit history . The 40th Infantry Brigade was originally made up of the 50th and 90th Infantry Regiments and served as part of the 20th Infantry Division from October 1918 to February 1919 . Based on the shoulder patch used by this unit , this unit must trace its lineage to that of the 40th Armored Brigade , who was authorized use of the same SSI on 2 February 1970 . Constituted in July 1917 the brigade was organized and drafted into federal service in August 1917 at Camp Kearny and was demobilized in April 1919 at the same location . June 1926 found the unit being reconstituted in the California National Guard . The unit headquarters relocated a number of times until it was called into federal service in February 1942 . After World War II the unit was inactivated in April 1946 , but was called up again in September 1950 due to the Korean War . Having wintered over in Korea in 1951 and 1952 the unit was deactivated in July 1954 . On 29 January 1968 , the 40th Infantry Division was deactivated and the 40th Infantry Brigade and 40th Armored Brigade were organized . On 13 January 1974 , the California Army National Guard was reorganized . The 40th and 49th Infantry and the 40th Armored Brigades were deactivated and the 40th Infantry Division was reformed . The 40th Infantry Brigade Combat Team ( IBCT ) was activated in 2005 as part of the reorganization of the California National Guard , which in turn was part of the restructuring of the total US Army . The Army is restructuring and moving from the division to the brigade as the primary building block of combat power . To this effect the 2nd and 3rd Brigades of the 40th Infantry Division of the California Army National Guard were merged into the 40th IBCT . As of February 2007 , most of the brigade is stateside . However , individual soldiers are in Iraq working in other active duty units or are tasked for border security missions in southern California . The 40th Infantry Brigade Combat Team is organized under the Army ' s new modular brigade structure . The role of the brigade combat team is to act as the Army ’ s basic tactical maneuver unit and the smallest combined - arms unit that can be committed independently . The brigade combat team is designed to conduct offensive , defensive , and stability operations . The core mission is to close with the enemy by means of fire and maneuver ; to destroy or capture enemy forces ; or to repel their attacks by fire , close combat , and counterattack . The brigade combat team can fight without augmentation , but it also can be tailored to meet the precise needs of its missions . 40th Infantry Brigade Combat Team also had a state mission . In times of emergency , the governor may call the National Guard to assist civil authorities . The self - contained and modular structure of the 40th Infantry Brigade Combat Team makes it well suited to provide this support . On 1 September 2007 , the brigade was again reformed after another reorganization of the 40th Infantry Division . However on 1 September 2008 the brigade was redesignated the 79th Infantry Brigade Combat Team ( United States ) .