Department of the Pacific (MarPac) was a United States Marine Corps ground training and administrative command established on November 15, 1920, which was responsible for the administration, training and equipment of the Marine Corps Units on the West Coast, 14th Naval District, 16th Naval District, 17th Naval District and Marine Forces in Northern China.

George Barnett was the 12th Commandant of the United States Marine Corps. He was a pioneer of amphibious warfare and the U.S. Marine Commandant during American involvement in World War I.