Most of this content comes from a website I created as part of a college class project; an extensive bibliography is included.
Prior to the enactment of the lottery in November 1969, the draft in the United States was not random, and focused almost entirely on age as the means by which it would be determined whether someone would be drafted or not, exclusive of any deferments they held. Per the Selective Service Act of 1948, all male citizens and aliens in the United States between the ages of eighteen and twenty-five inclusive were required to register with their local draft board, for selection for potential active-duty service for twenty-one months. After serving for this term, men had to serve in a reserve component for five years; to leave the military sooner, men could serve on active duty for another twelve months. Even though men had to register at eighteen, they could not be ordered to perform military service until the age of nineteen, however. In 1951, the term of active-duty service was extended from twenty-one months to twenty-four, the total period of military service from five years to eight, and the age at which men could be ordered to perform military service was lowered from nineteen years to eighteen years and six months.
President Harry S. Truman's Executive Order No. 9988 of August 20, 1948 and Executive Order No. 10001 of September 17, 1948 prescribed portions of the Selective Service regulations. After men had registered with their local draft board as soon as possible after attaining the age of eighteen years, their local draft board was to mail those men who had attained the age of nineteen years an SSS Form 100, or Classification Questionnaire, except in cases where men could be classified properly without this form. Men could substantiate their status as a conscientious objector by filling out an SSS Form 150. If a man classified as available for military service believed himself to actually suffer from a condition that disqualified him, he could request a medical interview.
The classifications remained essentially materially unchanged from Executive Order 10984 (January 5, 1962) onward:
Periodically, state Directors of Selective Service would order their local draft boards to supply numbers of registrants found qualified for military service to specific locations to be given Armed Forces Physical Examinations. If a man passed the examination, he would be given an NME Form 62, or Certificate of Acceptability. After a requisition was submitted by the Department of Defense to the national Director of Selective Service, he would issue to each state Director an SSS Form 200 (Notice of Call on State). The state Director would then issue to each of his local draft boards an SSS Form 201 (Notice of Call on Local Board). After receiving the form, each local draft board would select available men to be mailed an Order to Report for Induction (SSS Form 252). The men selected were to be those that the board had mailed a Certificate of Acceptability not less than twenty-one days prior to the date on which they were to be inducted. The date of induction was to be no less than ten days after the Order to Report for Induction was mailed.
By the time of the Gulf of Tonkin Resolution in August 1964, the order of selection for men not otherwise deferred was as follows. Men who had been deferred such that they were over the age of twenty-six after their deferment(s) expired remained in the eligible pool until the age of thirty-five, but were selected second-to-last.
1.) Delinquents who have attained the age of nineteen years in the order of their dates of birth with the oldest being selected first.
2.) Volunteers who have not attained the age of twenty-six years and in the sequence in which they have volunteered for induction.
3.) Nonvolunteers who have attained the age of nineteen years and have not attained the age of twenty-six years and who do not have a wife with whom they maintain a bona fide family relationship in their homes, in the order of their dates of birth with the oldest being selected first.
4.) Nonvolunteers who have attained the age of nineteen years and have not attained the age of twenty-six years and who have a wife with whom they maintain a bona fide family relationship in their homes, in the order of their dates of birth with the oldest being selected first.
5.) Nonvolunteers who have attained the age of twenty-six years in the order of their dates of birth, with the youngest being selected first.
6.) Nonvolunteers who have attained the age of eighteen years and six months and who have not attained the age of nineteen years, in the order of their dates of birth with the oldest being selected first.
Before August 26, 1965, those eligible registrants who were married and did not have children would be selected third, after the supply of delinquents, volunteers, and single nonvolunteers had been exhausted as a local board filled its quota.
On August 26, 1965, President Lyndon B. Johnson signed Executive Order 11241, which terminated the marriage deferment. President Johnson's executive order made it so that childless men who were married after August 26, 1965 would be considered the same as single men when selecting and ordering registrants to report for induction. A new group (Group 4) consisted of childless men who were married on or before August 26, 1965; these men would be selected next, after the supply of delinquents, volunteers, and single nonvolunteers and nonvolunteers who married after August 26, 1965 had been exhausted. The sequence of induction was thus modified.
1.) Delinquents who have attained the age of nineteen years in the order of their dates of birth with the oldest being selected first.
2.) Volunteers who have not attained the age of twenty-six years and in the sequence in which they have volunteered for induction.
3.) Nonvolunteers who who have attained the age of nineteen years and have not attained the age of twenty-six years and who (A) do not have a wife with whom they maintain a bona fide family relationship in their homes in the order of their dates of birth, with the oldest being selected first; or (B) have a wife with whom they married after August 26, 1965, and with whom they maintain a bona fide family relationship in their homes in the order of their dates of birth with the oldest being selected first.
4.) Nonvolunteers who have attained the age of nineteen years and have not attained the age of twenty-six years and who have a wife whom they married on or before August 26, 1965, and with whom they maintain a bona fide family relationship in their homes, in the order of their dates of birth, with the oldest being selected first.
5.) Nonvolunteers who have attained the age of twenty-six years in the order of their dates of birth, with the youngest being selected first.
6.) Nonvolunteers who have attained the age of eighteen years and six months and who have not attained the age of nineteen years in the order of their dates of birth, with the oldest being selected first.