In World War I, men were welcomed into the Army at recruit depots all over the United States, and then they reported directly to their service units where they were trained and sent overseas. When all deployable units were filled, extra men enlisting into the Army were kept at the recruit depots where they trained to be loss replacements. At least, that was the plan. Between 1917 and 1918, there never were extra men. In fact, the Army didn’t have enough men to fill the regular deployment units. So, the Army had to start tearing apart existing units and reassigning men to units that were ready to go overseas. With the Soldiers being shuffled around so much, units weren’t able to train Soldiers properly before they were sent into the war zone.
In World War II, the Army decided it needed a place for Soldiers to receive training before they were assigned to their regular units. So, starting in 1940, Soldiers were trained at replacement training centers before they were sent to the unit that they would serve with.
During this time, the process of training was standardized for each specialty, and field training exercises with live ammunition were added. Unfortunately, just like in WWI, in 1942, the Army ran out of the necessary manpower to fill deploying units, and after 1942, upon joining the Army, soldiers were immediately assigned to a unit and sent overseas without any training. As the war went on, the Army continuously struggled to develop a plan to meet the demands of battle.
After the war, the Army reduced its numbers, and it was finally able to commit energy to developing a training program. Early in 1946, the Army reduced the time Soldiers spent at replacement training centers by half by cutting out advanced individual training and concentrating on basic military training only. In 1947, the length of training returned to 13 weeks, but the focus remained on basic military training.
[…]During the Korean War, the Army pioneered a formal advanced individual training program. Formerly, Soldiers were given basic military training, and then they were assigned to a permanent unit where they would receive on-the-job training. In 1953, this pattern changed, and Soldiers were sent to specialty training after their basic training to learn the skills they would need for their particular job in the Army. In 1963, on the eve of the Vietnam War, the Army again improved the training program with the introduction of drill sergeants and committee groups to orchestrate training cycles. Drill sergeants, Soldiers specifically chosen for their leadership abilities and their accomplishments in the field, became the teachers, advisors, administrators, and leaders of basic training while committee groups, or specialty instructors, were placed in charge of hand grenades, infiltration courses, basic rifle marksmanship, night firing, close combat, individual tactics, and general subjects such as first aid.
