He spent his career mostly in Quartermaster Department of the Marine Corps beginning as private in the field assignments, ultimately reaching the general's rank and command of Depot of Supplies, Philadelphia during World War II.

[1] He was commissioned second lieutenant on June 14, 1917, and ordered to Marine Barracks Parris Island, South Carolina for duty as Depot Quartermaster with temporary rank of captain.

Following the war, Gregory was reverted to second lieutenant and ordered to Nicaragua for duty as post quartermaster with Marine detachment, Legation Guard at Managua in October 1920.

[1] Gregory then arrived to Marine Corps Base San Diego in June 1927 and served as post quartermaster until December 1928, when he sailed for his second tour of expeditionary duty in Nicaragua.

While in this capacity, he aided in relief work in connection with the earthquake at Managua in March 1931 and was commended by the secretary of the Navy and the Red cross.

[1][2][3][4] Assembly line production of military hardware and housekeeping supplies included hat ornaments, mosquito nets, mess pans, helmets, articles of uniforms, foot lockers, buckets, stoves, tent poles, bunks, etc.