United States Marine Corps School of Infantry

The School of Infantry (SOI) is the second stage of initial military training for enlisted United States Marines after Recruit Training. Since the initial training pipeline is divided between coasts, Marines from areas east of the Mississippi River usually graduate from MCRD Parris Island and move on to SOI at SOI East (located at Camp Geiger, a satellite facility of Camp Lejeune in North Carolina), while those from the western half of the nation attend MCRD San Diego and move on to SOI West at the Camp San Onofre area of Camp Pendleton in California. Female Marines are an exception, all of whom go through MCRD Parris Island and SOI East.

The School of Infantry's training mission ensures "Every Marine is, first and foremost, a Rifleman". At SOI, Marines with the Military Occupational Specialty of infantry (0300 occupational field) are trained at the Infantry Training Battalion (ITB), while all non-infantry Marines are trained in basic infantry and combat skills at the Marine Combat Training Battalion (MCT Bn). SOI marks a transition in the professional training of entry-level students from basically trained Marines to combat-ready Marines.

Prior to 1953, there was no formal infantry training in the Marine Corps, and all Marines received combat training at recruit training. The Marine Corps established Infantry Training Regiments at Camp Lejeune and Camp Pendleton in that year. Between 1954 & 1966, all Marines received 12 weeks of Boot Camp (Basic Training) and 8 weeks of Infantry Training Regiment (ITR) regardless of their Primary Military Occupational Specialty (MOS), growing out of the philosophy that all Marines are riflemen first. Due to manpower demands for Vietnam, in 1967 Boot Camp training was reduced from 12 weeks to 8 weeks, and ITR was reduced from 8 weeks to 4 weeks. In 1971, infantry skills training for non-infantry Marines was folded into recruit training and entailed only 60 training hours. During the late 1970s and through the 1980s, Marines assigned an Infantry MOS went to Infantry Training School, commonly referred to as "ITS". This lasted until the Marine Corps established Marine Combat Training as a 28-day course in 1989 to teach rifleman skills to all male Marines. In 1996, the 2nd Marine Division disbanded Division Schools, passing the role of advanced infantry training to the newly established Advanced Infantry Training Company at the School of Infantry (SOI). Prior to 1997, only male Marines were trained at SOI schools; females went directly to their MOS schools.

...
Wikipedia