Every Marine is first and foremost a rifleman – but after that, they come in all varieties.
There are hundreds of specialized jobs in the Marine Corps, ranging from machine gunner to upholsterer. An individual’s specialty might be defined by his pre-war experience (a waiter becoming a cook), his abilities in boot camp (a natural leader becoming a DI), his performance on aptitude tests (a mechanical wiz becoming an aviation crew chief), where his name fell in the alphabet (for the sake of expediency) or – very rarely – his personal preference. There were even administrators who were classified as experts in the classification of others. Of course, the needs of the Corps were paramount, which led to a great deal of dissatisfaction among recruits, though most either adapted to their new jobs or managed to switch once assigned to their permanent unit.
A three-digit system was employed to quickly identify an individual’s area of expertise. (A similar, four-digit system is in use today.) Beginning in 1944, these numbers were printed in the muster rolls of virtually every Marine Corps unit.
By looking at the MOS numbers, researchers can better determine what part an individual played in a battle. In the example above, there are several riflemen (745) and a BAR gunner (746). Though all on this list were PFCs at the time, Raymond Cable and Harold Carter had the extra responsibility of leading a fire team (653). It can be presumed that Otto Cesco and Joey Chalifour were acquainted – not only were they in the same company, but both were machine gunners (604) and hence in the same platoon.
Unfortunately, MOS interpretation is not always exact. Battle casualties might elevate an MOS 745 to the position of squad leader (737), but his primary qualification remains a rifleman. The assignation of 521 – “Basic” – could mean any number of jobs; a “Basic” Marine was one who either lacked a specialty or was in the process of switching positions. However, as a basic guideline, it serves its purpose.
In the biography pages, readers will note the use of numerous MOS codes. The most common of these appear below, but for a much more complete list please visit The Military Yearbook Project.
|345||Truck Driver, Light or Chauffeur|
|600||Machine Gun Squad Leader|
|604||Machine Gun Crewman|
|614||Mortar Squad Leader|
|653||Fire Team / Squad Leader (through end of 1944)|
|737||Fire Team / Rifle Squad Leader (1945)|