Origins of the USMC rank structure

E-1 Private – present since 1775; basic enlisted Marine.

E-2 Private First Class – added 1918, modeled after Army for WWI force integration.

E-3 Lance Corporal – historically an appointment below Corporal; revived formally in 1958 with the enlisted paygrade overhaul.

E-4 Corporal – in use since founding; junior NCO.

E-5 Sergeant – present since 1775; traditional squad/section leader.

E-6 Staff Sergeant – created 1923 to fill leadership gap between Sgt and GySgt.

E-6 Technical Sergeant (obsolete) – established 1941 during WWII expansion to recognize technical skills; insignia was three up, two down. It co-existed with Staff Sergeant but was eliminated in 1946/47 when enlisted grades were reorganized. Its duties were absorbed into Gunnery Sergeant, which became the standardized E-7 in 1959.

E-7 Gunnery Sergeant – originated 1899 for Marines serving aboard ships as ordnance/gunnery experts; eliminated in 1946, brought back in 1959 with its current insignia and role.

E-8 First Sergeant – evolved from “Orderly Sergeant” (1833) to “First Sergeant” (1872); command-track SNCO, abolished in 1947, restored 1955.

E-8 Master Sergeant – created 1946; technical counterpart to First Sergeant.

E-9 Sergeant Major – formalized in 1833, abolished in 1946, brought back 1954 as top enlisted leader in battalions/regiments.

E-9 Master Gunnery Sergeant – created 1935, eliminated in 1946, restored 1958/59 as apex of technical SNCO path.

Sergeant Major of the Marine Corps – created 1957 as the senior enlisted advisor to the Commandant; unique insignia with EGA and stars authorized in 1970.