At the beginning of World War II the 26th participated in the withdrawal of the Filipino and American forces on Luzon to the Bataan Peninsula. In a series of actions in December 1941 and early January of 1942, the regiment was essentially destroyed as an effective fighting force. It participated in the last horse-mounted combat by any American cavalry regiment. All other cavalry units in the U.S. Army were dismounted and converted to infantry, armor or service units prior to entering combat.

With the surrender of American forces on Bataan in April 1942 the regiment ceased to exist with most of the survivors becoming prisoners of war. Individual American officers and Filipino enlisted personnel continued to fight against the Japanese forces throughout the the war.

The regiment earned the Philippines Islands campaign streamer for World War II.

BLAZONRY Shield - Azure a sun in splendor with 12 wavy rays or. Crest - On a wreath of the colors a black horse's head charging erased at the neck bridled and a dexter cubit arm raised erased habited olive drab the hand grasping a saber at the charge all proper. Motto - Our strength is in loyalty. Distinctive Unit Insignia - The insignia is the crest and motto of the regiment. Source - QM 424.5 EP dated August 20, 1924. A letter to the Commanding Officer of the 26th Infantry from the Quartermaster General.