Due to the length, this comment will be split into a couple parts. Due to the commonality of the situation, I focus on the journey of the drafted infantry replacement. They journey of the voluntary enlistee was essentially the same; just substitute going to your local recruiting station and signing up versus being drafted.

The Draftee's Journey

Robert S. Rush’s book GI: The US Infantryman in World War II gives a very nice overview of the US infantryman’s experience in WWII, by using four vignettes, each of a fictional soldier in;

• Pacific Ocean Area (a “Michael O’Brien”, of the 165th Infantry Regiment, 27th Infantry Division. Michael voluntarily enlisted pre-war into the New York National Guard)

• North Africa and the Mediterranean (a “John Smith”, of the 1st Battalion, 133rd Infantry Regiment, 34th Infantry Division. John voluntarily enlists and is assigned as a replacement to the 76th Infantry Division, but is later transferred to the 34th Infantry Division after one of their companies suffers heavy losses at Kef al Ahmar Pass in March 1943)

• Europe (a “Joseph Stein”, of the 2nd Battalion, 22nd Infantry Regiment, 4th Infantry Division. Joseph is drafted, and later receives a field commission as an officer)

• Southwest Pacific (a “Gordon Cockrell”, of the 2nd Battalion, 382nd Infantry Regiment, 96th Infantry Division. Gordon is drafted, and initially assigned to the 89th Infantry Division, but is eligible for and attends Officer Candidate School and is later assigned to the 96th Infantry Division)

First, the seven draft registrations and draft classifications:

Draft Registrations:

Registration	Date	Criteria for Registration
1	October 16, 1940	Men who were 21-36 years old
2	July 1, 1941	Men who had turned 21 since October 16, 1940
3	February 14-16, 1942	Men who had turned 20 on or before December 31, 1941, and were not older than 45 by February 16, 1942
4	April 25-27, 1942	Men who were at least 45 on or before February 16, 1942 and not older than 65 on or before April 27, 1942 (not liable for military service)
5	June 30, 1942	Men born after January 1, 1922 and before June 30, 1924
6 (I)	December 10-31, 1942	Men born from July 1-December 31, 1924
6 (II)	January 1, 1943-March 31, 1947	Men born from January 1, 1925-March 31, 1929 (Men registered on their 18th birthdays)
7	November 16-December 31, 1943	Men living abroad aged 18-45

Draft Classifications 1940-1947:

Classification	Info
I	Available for service
I-A	Available for military service
I-A-O	Conscientious objectors eligible in a noncombatant role
I-B	Available for limited military service
I-B-O	Conscientious objectors available for limited service [not used after Aug. 18, 1942]
I-C	Members of land or naval forces of the United States
I-D	Students fit for military service; available not later than July 1, 1941
I-E	Students fit for limited military service; available not later than July 1, 1941
I-H	Men deferred by reason of age [not in effect]
II	Deferred because of occupation
II-A	Men necessary in their civilian activity
II-B	Men necessary to national defense
II-C	Men necessary to farm labor
III	Deferred because of dependents
III-A	Men with dependents not engaged in work essential to national defense [eliminated Oct. 1, 1943]
III-B	Men with dependents engaged in work essential to national defense
IV	Deferred by law or because unfit
IV-A	Men who had completed service [not considered in war]
IV-B	Officials deferred by law
IV-C	Non-declarant aliens
IV-D	Ministers of religion or divinity students
IV-E	Conscientious objectors available for civilian work of national importance
IV-E-LS	Conscientious objectors available for limited civilian work of national importance
IV-E-H	Men formerly classified in IV-E or IV-E-LS, deferred by reason of age
IV-F	Men physically, mentally or morally unfit

In the first through third registrations, draft order numbers were randomly assigned to registrants' cards, to be pulled from a glass bowl. In the fifth, sixth, and seventh registrations, order numbers were consecutively assigned based on birth date; the last order number of the third registration was advanced by one to give the first order number of the fifth registration, and the last number of the fifth registration was advanced by one for the first number of the sixth registration (the fourth registration, as it was simply a tally, was skipped)

Selective Training and Service Act of 1940:

The Selective Training and Service Act of 1940 provided for compulsory military service of some men aged 21-36 for one year; they could only be deployed in the western hemisphere or on US-held lands. It also stipulated that not more than 900,000 men were to be in training at any one time. To organize the peacetime draft registration, and other registrations after that, the Selective Service set up 6,443 draft boards nationwide. Each board covered a small area, usually a county; large cities such as New York had many boards, one for every 30,000 people. The board administered an eight-page questionnaire (DDS Form 40) and a basic physical and mental examination that assisted them in classifying men in their district. Each of the registrants who were eligible received a draft order number (in the case of the first draft call, 1 through 7,836) on the DDS Form 2, or draft registration card, that also had relevant personal information.

The very first draft call in October 1940 was symbolic; In Washington D.C., the numbers were placed into capsules and then into a large glass bowl. The bowl was stirred by Secretary of War Henry Stimson using a rod made from a beam of Philadelphia's Independence Hall. He then drew a number from the bowl and opened it. President Roosevelt announced the number; 158. Across the country, 6,175 men had that number on their cards. More numbers were drawn from the bowl until a reasonable number of men were inducted for military service. A full 50 percent of the men called to serve in October 1940 were rejected, 20 percent of these because they were illiterate by Army standards. In order to be preliminarily classified I-A by their local board during the peacetime draft in October 1940, a man needed to;

• Be between five and six and a half feet tall and weigh at least 105 pounds

• Have at least 12 teeth (6 incisors and 6 chewing teeth)

• Not have venereal disease, hernia, or flat feet

• Have vision correctable with glasses

• Be functionally literate and able to write

• Not have been convicted of a crime

Starting on July 1, 1941, men who were 28 and older were released from service and were also deferred from being drafted. The term of service of the October draftees was unpopularly extended for eighteen more months on August 18, 1941. With US entry into WWII, the term of service was extended again, for the duration of the war plus six months.

Draft Modifications:

On December 5, 1942, through signing Executive Order 9279, President Roosevelt barred men who were 18 to 37 years old from voluntarily enlisting into the military, in order to preserve the nation's war manpower. Men of these ages could now only join the military by being eligible to be drafted. Men who were 17, and those who were 38 to 45 who were not engaged in a war-critical industry (or deferred from the draft for any other reason) could still enlist voluntarily, provided they met the military's qualifications. The order became effective on January 1, 1943 and expired on September 7, 1945.

The Selective Service drafted under a quota of 200,000 eligible men per month. After a request was made by the armed forces through Selective Service headquarters, the Selective Service assigned a proportioned quota to each state. Based upon the pre-selected draft order numbers for that period, local draft boards notified the registrants who had been selected, and ordered them to report for induction. The basic medical standards listed above held true for the majority of WWII. Beginning in 1943, many minor felons (100,000 eventually were drafted) that were previously classified IV-F were administratively pardoned by draft boards in co-operation with local police departments, making them liable for induction. In October 1943, fathers whose children were born before December 7, 1941 began to be drafted. By April 1944, the Army further relaxed the induction criteria as they proved to be too disqualifying in some cases. Men could now be completely toothless, be missing one or both external ears, or be missing a thumb or three fingers (but not both) on one hand only. Mild cases of certain venereal diseases were also acceptable, to be treated with the new drug penicillin after induction.