9 October, 1917

The 8th Marines was activated at Quantico, Virginia. Although the regiment would not see combat in Europe during World War I, the officers and enlisted men of the 8th Marines participated in operations against dissidents in Haiti for over five years during the 1920s. During World War II, the regiment was assigned to the 2d Marine Division and participated in combat operations on Guadalcanal, Tarawa, Saipan, Tinian, and Okinawa, and earned three Presidential Unit Citations.