As of 1933, the squadron was headquartered at Fort Ringgold, near Rio Grande City, the Second of the 12th rode patrols along the southern border for almost forty years under different headquarters. Late in 1940, the battalion returned to Fort Bliss and trained for war as part of the 1st Cavalry Division's Second Brigade and participated in the Louisiana Maneuvers.
The battalion traded its horses for jeep and amphibious assault vehicles in February 1943. In mid-June 1943, the Division shipped out for Australia, where it trained in preparation for combat on the Pacific Rim. The battalion saw its first combat on Los Negros Island in March 1944.
The battalion also participated in the invasion of the Philippines. Landing on Leyte on 20 October 1944, the regiment was assigned the most difficult terrain in the central mountain ranges and faced fierce fighting. The fight was characterized by the bloody fight for Hill 2348 on 15 November. After being cut off from their supply lines, the battalion held off waves of suicide attacks. Finally on the night of 2 December, the troopers counterattacked and took the hill. The First Team lost 241 killed in action during the fighting on Leyte.
On 27 January, the battalion stormed ashore on Luzon. It took six months, but on 30 June 1945, the entire island was secured. Selected by MacArthur to be the first into Japan, the battalion took on occupation duty near Yokohama until its deactivation in 1949.
Reactivated in 1957, the battalion deployed to Vietnam in 1965 and fought the division's first engagement from 18 to 20 September as part of Operation Gibraltar. On 2 February 1968 during the Battle of Huế the battalion was deployed from Camp Evans to PK-17 to launch an attack towards La Chu to close off the PAVN supply routes west of Huế. The 2/12th Cavalry was pinned down by superior PAVN forces and eventually broke out on the night of 3 February leaving their dead behind. The battalion participated in the Cambodian Incursion and earned its 16th campaign streamer for the Sanctuary Counteroffensive. Serving as battalion signal officer during the Battle of Khe Sanh was future U.S. Senator Max Cleland.
The unit was reactivated in 1986, with the mission of training Armor officers at Fort Knox. The battalion's colors were later moved to the First Team (i.e. 1st Cavalry Division) at Fort Hood, Texas in December 1992. Since then, the Chargers have served at places like the National Training Center at Fort Irwin, California. In the summer of 1995, Alpha company was called out with Task Force 1–5 CAV on a contingency response to hostilities in the Persian Gulf. A year later, from September to December 1996, Bravo and Charlie company deployed with Task Force 1–5 Cavalry again, this time as a part of 3rd Brigade for Operation Desert Strike. Despite not being on an alert status, Bravo and Charlie companies mustered, deployed, drew propositioned equipment and occupied defensive battle positions in 96 hours.