United States Marine Corps off-base, except in transit to and from their place of duty and in the event of an emergency. As in any military organization, the official and unofficial traditions of the Marine Corps serve to reinforce camaraderie and set the service apart from others. The Corps' embrace of its rich culture and history is cited as a reason for its high "esprit de corps". The "Marines' Hymn" dates back to the 19th century and is the oldest official song in the United States armed forces. The Marine motto "Semper Fidelis" means "Always Faithful" in Latin, often appearing as "Semper Fi"; also
Organization of the United States Marine Corps Organization of the United States Marine Corps The United States Marine Corps is organized within the Department of the Navy, which is led by the Secretary of the Navy (SECNAV). The most senior Marine commissioned officer is the Commandant of the Marine Corps, responsible for organizing, recruiting, training, and equipping the Marine Corps so that it is ready for operation under the command of the unified combatant commanders. The Marine Corps is organized into four principal subdivisions: Headquarters Marine Corps, the Operating Forces, the Supporting Establishment, and the Marine Forces Reserve. The Operating Forces are further subdivided into three categories: