That same month, they redeployed with the brigade to Galveston, Texas, in case of any German operation in the Caribbean or in Mexico.

[1][2] On December 1, 1925, the regiment was reactivated as a reserve organization whose mission was to train and maintain at a high degree of preparedness a group of “civilian” Marines.

[1] The regiment was reformed on 17 March 1952 at Camp Pendleton, California and assigned to the 3d Marine Division.

On March 8, 1965, the 9th Marine Regiment came ashore at Red Beach as the first conventional ground combat unit in South Vietnam, their mission was to defend the Da Nang Air Base.

The 9th Marines served as a vital stop to the People's Army of Vietnam (PAVN) penetrations across the DMZ and from along the Ho Chi Minh Trail in Laos.

In Operation Buffalo, elements of the 1st Battalion, 9th Marines made contact north of Con Thien with regimental-size PAVN forces in an engagement that lasted through May, accounting for over 1300 enemy dead.

[4][5] General Richard G. Stilwell wrote in his report to COMUSMACV General Creighton Abrams on Operation Dewey Canyon: “...this ranks with the most significant undertakings of the Vietnam conflict in the concept and results...”[6] The 9th Marines were part of the first redeployments from Vietnam in the summer of 1969.

In July 1969 the regiment deployed to Camp Schwab, Okinawa and was reassigned in August 1969 to the 9th Marine Amphibious Brigade.