Culture of the United States Marine Corps
Two styles of swords are worn by Marines. The Marine Corps officers' sword is a Mameluke Sword, similar to the Persian shamshir presented to Lt. Presley O'Bannon after the Battle of Derna during the First Barbary War. After its adoption in 1825 and initial distribution in 1826, Mameluke Swords have been worn by Marine officers ever since, except during the period 1859–1875, when they were required to wear the Army's Model 1850-foot officers' sword. Upon returning to the traditional sword, many officers gave their Army swords to their senior noncommissioned officer, creating the basis for the NCO sword. Generally, Marines are the only branch where enlisted members regularly carry a sword (the Army authorizes platoon and first sergeants to carry a Model 1840 sword during some ceremonies, while the Chief of Naval Operations authorized Chief Petty Officers and above to carry an optional ceremonial cutlass with dress uniforms in 2010).
Line officer
In the United States Marine Corps (and USMC Reserve), all officers – including warrant officers and limited duty officers (LDOs) – are line officers, trained to command combat units, although Marine officers cannot command ships or shore organizations of the Navy. Unlike the Navy, the Marine Corps does not have any staff corps, consequently all Marine engineer and supply officers, and judge advocates, are line officers. The Marine Corps has no medical corps officers, dental corps officers, nurse corps officers, or chaplain corps officers. Because the Marine Corps is a service within the Department of the Navy, these staff corps billets in the Marine Corps are normally filled by US Navy staff corps officers in those specialties, serving alongside Marines in Marine units, although officers of the commissioned corps of the Public Health Service may be detailed, as well.