The 45^th Quartermaster Regiment with three battalions was originally constituted on 1 May 1936. It was redesignated as the 45^th Quartermaster Truck Regiment (Colored) on 1 April 1942 and activated at Oakland Sup-port of Embarkation on 9 May 1942. It served as a replacement pool unit. On 21 December 1942, the regiment moved to Camp Stoneman, California, near San Francisco. On 31 December 1942, the regiment was removed from the replacement pool list and ordered to prepare for movement again.

On 7 September 1943, it embarked from Los Angeles Port of Embarkation, Wilmington, California, and arrived in India on 20 November 1942. On 1 December 1943, the Regiment was broken up and the units were redesignated. The 45^th Quartermaster Truck Regiment became the 45^th Quartermaster Group with the 1^st Battalion redesignated the Headquarters and Headquarters Detachment, 45^th Quartermaster Battalion, Mobile and the 2^nd Battalion became 68^th Quartermaster Battalion, Mobile. The Companies A through M were also redesignated to numbered companies, 3461^st through 3472^th, and followed separate lineages. The 45^th Battalion kept the 3461^st through 3465^th Companies.

The three original battalions continued to serve under the 45^th QM Group in the China-Burma-India Theater. The 45^th QM Group embarked from the Karachi Port of Embarkation, Karachi, India, on 4 November 1945 and disembarked at New York Port of Embarkation. The unit was once inactivated on 26 November 1945 at Camp Kilmer, New Jersey.

After the helicopter came into prominence in the US Army, the battalion was redesignated the Headquarters and Headquarters Detachment, 45^th Transportation Battalion (Helicopter) on 1 March 1954. It was activated in Korea on 1 April 1954. The battalion served in Korea until 5 January 1955 when it was transferred (less personnel) from Armed Forces Far East to Fort Sill, Oklahoma to form the nucleus of the Helicopter Training Command. While at Fort Sill, the battalion took part in numerous large field exercises. It served as the headquarters for the AAUTC, taking its part in the job of transitioning pilots for all parts of the world, and the formation of Helicopter companies.

On 1 July 1962, the 45^th Transportation Battalion (Transport Aircraft) went to Vietnam on temporary duty from Okinawa. At this time, the Army only supported the training of the Army of the Republic of South Vietnam (ARVN). Other than advisors, the first units to arrive in Vietnam were helicopter Transportation units. On 22 March 1963, the 45^th Battalion status changed from Temporary Change of Station to Permanent Change of Station to Vietnam. During this time, it received the Hughes Army Aviation Trophy for support of Army mission. For its services in Vietnam, the battalion received the Vietnam Army Cross. It had responsibility for the following:

• HHD
• 8^th Transportation Company (Light Helicopter)
• 81^st Transportation Company (Light Helicopter)
• 18^th Aviation Company (Fixed Wing Light Transport)
• 57^th Medical Detachment (Helicopter)
• 19^th Quartermaster Detachment (Petroleum Quality Surveillance)
• 22^nd Quartermaster Detachment (Petroleum Bulk Storage and Issue)
• 24^th Quartermaster Detachment (Petroleum Bulk Storage and Issue)

HHD, 45^th Battalion was redesignated HHD, 145^th Combat Aviation Battalion on 24 September 1963. It remained in Vietnam until 2 April 1972.