On December 1, 1969, the Selective Service System of the United States conducted two lotteries to determine the order of call to military service in the Vietnam War for men born from 1944 to 1950. These lotteries occurred during a period of conscription from just before World War II to 1973.
The lottery numbers assigned in December 1969 were used during calendar year 1970 both to call for induction and to call for physical examination, a preliminary call covering more men.
The days of the year (including February 29) were represented by the numbers 1 through 366 written on slips of paper. The slips were placed in separate plastic capsules that were mixed in a shoebox and then dumped into a deep glass jar. Capsules were drawn from the jar one at a time.
The first number drawn was 258 (September 14), so all registrants with that birthday were assigned lottery number 1. The second number drawn corresponded to April 24, and so forth. All men of draft age (born 1944 to 1950) who shared a birth date would be called to serve at once. The first 195 birthdates drawn were later called to serve in the order they were drawn; the last of these was September 24.
Also on December 2, 1971, a second lottery was held, with the 26 letters of the alphabet. Among men with the same birthdate, the order of induction was determined by the permutation ranks of the first letters of their last, first, and middle names. Anyone with initials "JJJ" would have been first within the shared birthdate, followed by "JGJ", "JDJ", and "JXJ"; anyone with initials "VVV" would have been last.
People soon noticed that the lottery numbers were not distributed uniformly over the year. In particular, November and December births, or dates 306 to 366, were assigned mainly to lower draft numbers representing earlier calls to serve (see figure). This led to complaints that the lottery was not random as the legislation required. Analysis of the procedure suggested that mixing 366 capsules in the shoe box did not mix them sufficiently before dumping them into the jar. ("The capsules were put in a box month by month, January through December, and subsequent mixing efforts were insufficient to overcome this sequencing.") Only five days in December—Dec. 2, 12, 15, 17 and 19—were higher than the last call number of 195; had the days been evenly distributed, 14 days in December would have been expected to remain uncalled. From January to December, the rank of the average draft pick numbers were 5 4 1 3 2 6 8 9 10 7 11 12. A Monte Carlo simulation found that the probability of a random order of months being this close to the 1–12 sequence expected for unsorted slips was 0.09%.
Draft lotteries were conducted again in 1971 (for those born in 1952) and 1972 to 1976 (for 1953 to 1956 births). The draft numbers issued in 1972 were never used to call for induction into service, because the last call was December 7 and authority to induct expired June 30, 1973.
The 1972 to 1975 lottery numbers were used to call some men born 1953 to 1956 for physical exams. The highest number called for a physical was 215 (for tables 1970 through 1976).
Origins and consequences
Previously in the United States, during the War of 1812, President Madison established a commission to recommend the best ways to raise military manpower, to keep the draft or to institute a volunteer army.
After much debate within the Nixon administration and Congress, it was decided that an all-volunteer force was affordable, feasible, and would enhance the nation’s security. U.S. President Richard Nixon issued an Executive order prescribing regulations for random selection of the United States Selective Service system on November 26, 1969.
The 1970s were a time of turmoil in the United States, beginning with the Civil Rights Movement which set the standards for practices by the anti-war movement. The 1969 draft lottery only encouraged resentment of the Vietnam war and the draft. It strengthened the anti-war movement, and all over the United States people decried discrimination by the draft system "against low-education, low-income, underprivileged members of society".
The draft lottery had social and economic consequences because it generated resistance to military service and the resisters, draft evaders or "draft dodgers", were generally young, well educated, healthy men. The fear of military service in Vietnam influenced many young men born in the late 1940s to join the National Guard. These young men knew, in advance, that the National Guard would be unlikely to send its soldiers to Vietnam. Many men were unable to join the National Guard, even though they had passed their physicals, because many state National Guards had long waiting lists just to enlist. Still others chose legal sanctions such as imprisonment, either showing their disapproval by burning their draft cards or draft letters, or simply not presenting themselves for the military service test. Others left the country, commonly moving to Canada. The number of American citizens who moved to Canada during the Vietnam war because of the draft is estimated to be around 125,000; it is believed that about half returned to the United States after the Nixon era (when the war was also over)(1975).
Lottery procedure was improved the next year although public discontent continued to grow until "authority to induct expired on June 30, 1973".
In 1970, covering 1951 birthdates for use during 1971 (sometimes called the 1971 draft), scientists at the National Bureau of Standards prepared 78 random permutations of the numbers 1 to 366 using random numbers selected from published tables. From the 78 permutations, 25 were selected at random and transcribed to calendars using 1 = January 1, 2 = January 2, ... 365 = December 31. Those calendars were sealed in envelopes. 25 more permutations were selected and sealed in 25 more envelopes without transcription to calendars. The two sets of 25 envelopes were furnished to the Selective Service System.
On June 2, an official picked two envelopes, thus one calendar and one raw permutation. The 365 birthdates (for 1951) were written down, placed in capsules, and put in a drum in the order dictated by the selected calendar. Similarly, the numbers from 1 to 365 were written down and placed into capsules in the order dictated by the raw permutation.
On July 1, the drawing date, one drum was rotated for an hour and the other for a half-hour (its rotating mechanism failed). Pairs of capsules were then drawn, one from each drum, one with a 1951 birthdate and one with a number 1 to 366. The first date and number drawn were September 16 and 139, so all men born September 16, 1951, were assigned draft number 139. The 11th draws were the date July 9 and the number 1, so men born July 9 were assigned draft number 1 and drafted first.