<P> Due to its emphasis on small - unit tactics, its infantry - centric ethos, and its tradition of empowering junior NCOs to exercise first - level leadership, the U.S. Marine Corps' Tables of Organization (TOs) usually places corporals (as well as sergeants and staff sergeants) in billets where other services would normally have higher ranking NCOs in authority . For example, the USMC Table of Organization "billet" rank for rifle fire team leader, rifle squad leader, and rifle platoon sergeant is corporal (E-4), sergeant (E-5), and staff sergeant (E-6), respectively . However, the same positions (Table of Organization and Equipment "slots") in US Army infantry units are one grade higher and, except in fire teams (both services with four men in each team), the equivalent Army units are smaller (viz., USMC rifle squad and rifle platoon - 13 men and 43 men, respectively, vice US Army rifle squad and rifle platoon - 9 men and 34 men, respectively). Specifically, for the Army rifle units, the rank of the fire team, squad leader, and platoon sergeant are: sergeant (E-5), staff sergeant (E-6), and sergeant first class (E-7), respectively . Similarly, the term "strategic corporal" refers to the special responsibilities conferred upon a Marine corporal over against the normal responsibilities, and usual authority, of service members in the grade of E-4 in the other branches of the U.S. Armed Forces . </P> <P> Until the mid-to - late 1980s, corporals were the lowest USMC rank eligible for selection as a drill instructor for USMC recruit training . </P> <P> The history of the rank of corporal in the USMC roughly parallels that of the U.S. Army until 1942 . From 1775 until WWII, the Marine Corps used essentially the same rank and organizational structure as its common British and colonial forebears with the Army, as well as the later Continental and U.S. armies . In 1942, as the Army modified its triangular division infantry organization to best fight in the European / North African / Middle Eastern Theatre the Marine Corps began modifying the triangular division plan to best employ its amphibious warfare doctrine in the Pacific Theatre . This meant that for the Corps, squad leaders would remain as sergeants and that the rifle squad would be sub-divided into three four - man fire teams each led by a corporal . </P> <Table> <Tr> <Th_colspan="11"> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> United States enlisted ranks </Th> </Tr> <Tr> <Th> Pay grade → Branch of service ↓ </Th> <Th> E-1 </Th> <Th> E-2 </Th> <Th> E-3 </Th> <Th> E-4 </Th> <Th> E-5 </Th> <Th> E-6 </Th> <Th> E-7 </Th> <Th> E-8 </Th> <Th> E-9 </Th> </Tr> <Tr> <Td> Army </Td> <Td> PVT </Td> <Td> PV2 </Td> <Td> PFC </Td> <Td> SPC--CPL </Td> <Td> SGT </Td> <Td> SSG </Td> <Td> SFC </Td> <Td> MSG--1SG </Td> <Td> SGM--CSM--SMA </Td> </Tr> <Tr> <Td> Marine Corps </Td> <Td> Pvt </Td> <Td> PFC </Td> <Td> LCpl </Td> <Td> Cpl </Td> <Td> Sgt </Td> <Td> SSgt </Td> <Td> GySgt </Td> <Td> MSgt--1stSgt </Td> <Td> MGySgt--SgtMaj--SgtMajMarCor </Td> </Tr> <Tr> <Td> Navy </Td> <Td> SR </Td> <Td> SA </Td> <Td> SN </Td> <Td> PO3 </Td> <Td> PO2 </Td> <Td> PO1 </Td> <Td> CPO </Td> <Td> SCPO--CMDCS </Td> <Td> MCPO--CMDCM--FORCM, FLTCM--MCPON </Td> </Tr> <Tr> <Td> Air Force </Td> <Td> AB </Td> <Td> Amn </Td> <Td> A1C </Td> <Td> SrA </Td> <Td> SSgt </Td> <Td> TSgt </Td> <Td> MSgt--1st Sgt </Td> <Td> SMSgt--1st Sgt </Td> <Td> CMSgt--1st Sgt--CCM--CMSAF </Td> </Tr> <Tr> <Td> Coast Guard </Td> <Td> SR </Td> <Td> SA </Td> <Td> SN </Td> <Td> PO3 </Td> <Td> PO2 </Td> <Td> PO1 </Td> <Td> CPO </Td> <Td> SCPO </Td> <Td> MCPO--CMC--Area CMC, CGRF - CMC--MCPOCG </Td> </Tr> </Table>

When was the rank of corporal established in the marine corps