The US Army's manpower shortage was largely, but not completely, a result of their own doing and not the result of an actual shortage of bodies. In the Victory Program of fall 1941, the Army had outlined a force of 213 divisions that it would need to take on Germany. This program had hypothesized that Germany would defeat the Soviet Union and the United States and Great Britain would have to take on Germany alone, which meant a far larger number of German troops would be facing the two countries. Fear of the German blitzkrieg (a fear which proved to be unfounded) resulted in a massive expansion of the antiaircraft and tank destroyer arms. This massive initial unit expansion made it difficult to staff them. It was originally planned to have 222 tank destroyer battalions, but this figure was later reduced to 106 in March 1943, and 78 in October 1943. Due to the lack of enemy aircraft in Italy, a provisional infantry regiment (the 473rd) was constituted out of the headquarters of the 2nd Armored Group and the 434th, 435th, 532nd and 900th Antiaircraft Artillery Automatic Weapons battalions.

A major problem which constricted America's manpower during WWII was their industrial and agricultural capacity and its value to the Allies. As a result, in 1942 Army planners shortsightedly estimated the maximum number of men which could be brought into the service of the United States without disrupting these critical areas was about 10.5 million, out of an eligible population of twenty-five million, about 7.8 percent of the US population. In reality, the maximum population of these men which could be brought into service was about fifteen to sixteen million.

On December 5, 1942, President Franklin D. Roosevelt signed an executive order reducing the draft age from 21-37 to 18-38, and eliminating voluntary enlistment in order to avoid straining the war economy and controlling the amount of men the armed forces received at a time. Men aged 17, and those aged 38-45 could still voluntarily enlist if they met the armed forces' qualifications.

By the middle of 1943, the Selective Service was falling behind on its inductions (a planned 200,000 men per month). Back in October 1941, 10 million out of 16 million Selective Service registrants were classified as III-A, "Men with dependents, not engaged in work essential to national defense" and were deferred. A major cause of this induction shortfall was the continued refusal to draft these men who had dependents. The Selective Service estimated a shortfall of nearly 450,000 if it didn't draft these men. On October 1, 1943, the Selective Service administratively eliminated the III-A classification and began to draft those fathers whose children were born before December 7, 1941.

Number of Fathers Drafted

Month(s)	Fathers drafted	Percent of monthly inductees
October 1943	13,300	6.8
November 1943	25,700	13.4
December 1943	51,400	26.4
April 1944	114,600	52.8
October 1943-December 1945	944,426	30.3

By V-J Day, of the 6.2 million classified fathers aged 18-37, 20 percent had been inducted. Of those 18-25, 58.2 percent were on active duty.

In late 1943, the maximum size of the Army was reduced from 8.2 million to 7.7 million and 100-125 divisions. This program was further modified by reducing the number of divisions to the already-activated 88, (three more divisions would later be activated, bringing the final Army total to 91) and deleting 15 divisions scheduled for activation in 1943. Meanwhile, divisions were accumulating in the United States due to the uncertain strategic situation in Europe (the proposed Operation Roundup, a cross-channel invasion of France in late 1942 had been cancelled) The Army was struggling to fill the 7.7 million quota, being short nearly 200,000 men.

By early 1944, the Army Ground Forces was short between 87,000-97,000 men due to the inadequacy of replacement training programs to produce enough infantrymen to refill divisions which had taken casualties. The initial War Department figure for the percentage of replacements that needed to be trained as infantry was 64.3; by April 1944 this had been raised to 70.3 percent. Fighting in Normandy soon proved that this figure was far too low; estimates were that 90 percent of Army Ground Forces casualties occurred in the Infantry.

Also by early 1944, 100,000 men, mostly service troops, had been "saved" by economizing the organization and activation of units, but the needs of the new B-29 program stripped these men away; the Army Air Forces had asked for 130,000 men to staff it. This resulted in a serious shortage of the potential number of service troops that could be deployed overseas. As a result of this shortage, trained divisions in the US that were ready for deployment were used to perform "housekeeping", running training camps and the like. In February 1944, the laboring Army Specialized Training Program was cut back from 150,000 to 30,000 men, releasing 120,000 men for overseas duty; many of the later divisions to enter combat had a high percentage of former ASTP men. On January 19, 1944, it was authorized to strip divisions still in the United States for replacements, sending nearly 100,000 qualified men from fully-staffed divisions overseas. Note that the figure for infantry replacements had proven far too low.

Number of Men Stripped From Divisions, April-September 1944 by Division and Branch

Division	Infantry	Field Artillery	Cavalry	Armored	Airborne Infantry	Total
13th A/B	1,172 Pvt.	--	--	--	580 Pvt.	1,652
8th Armd.	1,150 Pvt.	40 NCO, 420 Pvt.	33 NCO, 207 Pvt.	570 Pvt.	--	2,420
13th	1,800 Pvt.	40 NCO, 460 Pvt.	9 NCO, 260 Pvt.	610 Pvt.	--	3,179
16th	1,597 Pvt.	39 NCO, 475 Pvt.	45 NCO, 235 Pvt.	15 NCO, 541 Pvt.	--	2,947
20th	1,459 Pvt.	49 NCO, 1,450 Pvt.	20 NCO, 208 Pvt.	660 Pvt,	--	2,846
42nd Inf.	372 NCO, 3,564 Pvt.	69 NCO, 771 Pvt.	45 Pvt.	--	--	4,821
63rd	278 NCO, 3,290 Pvt.	579 Pvt	5 NCO, 33 Pvt.	--	--	4,185
65th	5,222 Pvt.	314 Pvt.	45 Pvt.	--	--	5,581
66th	3,999 Pvt.	840 Pvt.	5 NCO, 38 Pvt.	--	--	4,882
69th	102 NCO, 4,312 Pvt.	143 NCO, 697 Pvt.	5 NCO, 40 Pvt.	--	--	5,299
70th	41 NCO, 2,804 Pvt.	6 NCO, 474 Pvt.	5 NCO, 40 Pvt.	--	--	3,370
71st	3,172 Pvt.	36 NCO, 294 Pvt.	--	--	--	3,502
75th	4,459 Pvt.	70 NCO, 710 Pvt.	5 NCO, 40 Pvt.	--	--	5,284
76th	516 NCO, 5,730 Pvt.	69 NCO, 711 Pvt.	5 NCO, 40 Pvt.	--	--	7,071
78th	4,698 Pvt.	50 NCO, 730 Pvt.	1 NCO, 44 Pvt.	--	--	5,523
86th	4,050 Pvt.	50 NCO, 670 Pvt.	40 Pvt.	--	--	4,810
87th	3,850 Pvt.	38 NCO, 680 Pvt.	40 Pvt.	--	--	4,610
89th	2,700 Pvt.	360 Pvt.	--	--	--	3,060
97th	5,064 Pvt.	57 NCO, 279 Pvt.	9 NCO, 21 Pvt.	--	--	5,430
100th	125 NCO, 3,550 Pvt.	--	--	--	--	3,675
103rd	2,550 Pvt.	--	--	--	--	2,550
106th	366 NCO, 3,859 Pvt.	57 NCO, 723 Pvt.	45 Pvt.	--	--	5,050

Another problem bugging the Army from 1942-1944 was the number of 18 year old draftees it was receiving. In May 1943, it was decided that 18 and 19 year old inductees would be assigned to units in training and unlikely to deploy overseas soon only, and inductees 20 or over would mostly be assigned as replacements. As the Italian campaign intensified in late 1943, the need for replacements became acute. On February 26, 1944, the War Department issued a ban on using 18 year olds and "pre-Pearl Harbor" fathers as replacements unless they had at least six months' training; men from any other source were to be taken first. On June 24, 1944, the ban became even more rigid, with no man under 18 years and six months old to be assigned to an infantry or armored replacement center, and no man under nineteen to be assigned as an overseas replacement. More than 37,000 men were affected, unable to be shipped outside the United States. As a result, it was necessary to "store" these men until they became of age by assigning them to units still in the United States and not likely to deploy anytime soon.

By August 1, 1944, the ban had proven very problematic, and was rescinded; 18 year olds began to be shipped as overseas replacements again in December 1944. On December 8, 1944, the US Third Army was short 11,000 infantrymen; this was only four percent of the Third Army's total strength, but actually the rifle strength of nearly two infantry divisions.

Another problem in the Army in the WWII period was segregation. African-Americans made up nearly 10 percent of the US population, and restricting them solely to service units or rejecting them entirely based upon their education or AGCT scores deprived the Army of a large portion of potential combat manpower.

Sources:

US WWII draft classifications

US Army in World War II, by Rich Anderson

"Daddy's Gone To War": The Second World War in the Lives of America's Children, by William M. Tuttle, Jr.

The Tank Killers: A History of America's World War II Tank Destroyer Force, by Harry Yeide

The Procurement and Training of Ground Combat Troops, by hy Robert R. Palmer, Bell I. Wiley, and William R. Keast (Historical Section Army Ground Forces)

The 90-Division Gamble, by Maurice Matloff