Throughout their existence, Army Ground Forces were the largest training organization ever established in the United States.

The headquarters was partially activated on 26 July 1940 at the United States Army War College, Washington, D.C.

As World War II approached, the role of GHQ remained a training function and a few months after Pearl Harbor, the command was redesignated as HQ, Army Ground Forces in recognition of its revised mission.

This was partially because requirements for service troops and overhead was greater than anticipated, and because the Army's overall strength became fixed at a lower level than expected.

Fortunately, these sufficed to bring about the defeat of Germany and Japan, largely because the Soviet Union carried most of the burden of fighting the German Army on the Eastern Front.

[13] Energetic and painstaking efforts were made by Army Ground Forces to optimize the divisions for combat operations.

[18] Between April and September 1944, as casualties in Normandy began to bite, some 91,747 men were stripped from twenty-two divisions in the United States.

As casualties mounted, a massive comb-out began as the Army Ground Forces struggled to provide replacements.

Personnel from non-combat assignments were pulled from duty, hastily trained, and then reassigned to units as combat infantry replacements.

For into the planning of the organization, training, and equipment of this unit was poured the accumulated experience of four years' intensive effort.

But, mainly because of personnel exigencies the control of which lay beyond the jurisdiction of the Army Ground Forces, the 65th was about the least ready for combat of all divisions trained in World War II.

General MacArthur felt that they had insufficient firepower, and they performed unsatisfactorily in training maneuvers, so the 71st and 89th were converted to regular infantry divisions.

Despite its jungle training, the 71st Infantry Division was rushed to Europe in response to the German Ardennes Offensive.

[25] Five airborne divisions (11th, 13th, 17th, 82nd and 101st) were formed, but as early as the Allied invasion of Sicily (Operation Husky) in July 1943 it was apparent that there would not be sufficient troop carrier aircraft to employ them in the manner for which they had been intended.

The 11th Airborne Division in the South West Pacific Area (SWPA) remained on the old AGF establishment.

Once the Allied Air Forces began to get the upper hand, demand tapered off and it became apparent that anti-aircraft units had been over-produced.

[29] Opposition from Army Ground Forces was one of the primary factors for the late and limited introduction of the M26 Pershing into the European Theater.

In process, the number of non-divisional tank battalions increased to 65, permitting more combined training with the infantry divisions.

While the old armored division organization was cumbersome and inefficient, the new was flexible but sometimes too lean and light, requiring supplementing.

However, by the time it embarked, the defense of Australia was no longer paramount and it served in the South West Pacific Area in the dismounted role.

[34] Two non-divisional cavalry regiments served as infantry in the South West Pacific Area and China Burma India.

However, they only spent about 6% of their time on reconnaissance tasks, leading to a postwar consensus that either they lacked the combat power to perform their assigned role or had simply been misused altogether.

[36] This decision was reversed after the towed battalions lost large numbers of guns over-run or stuck in mud and snow during the Ardennes offensive.

Later, good self-propelled gun carriages became available, but massed enemy armor became scarce and most tank destroyer units began operating as field artillery.