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How did the draft lottery numbers determine order of call-up during Vietnam?
Executive summary
The 1969–72 Vietnam draft lotteries assigned every birth date (including Feb. 29) a random number from 1–366; men with lower numbers were called before those with higher numbers for induction [1] [2]. The drawing was done by placing 366 slips in plastic capsules and drawing them by hand to set the sequence; subsequent analysis and lawsuits argued the 1969 drawing was not perfectly random and tended to disadvantage some birth‑months [3] [4] [5].
1. How the lottery physically worked: balls, capsules and birthdays
The Selective Service printed all 366 calendar dates, placed each date on a slip and put those slips into blue plastic capsules; the capsules were mixed and then drawn one at a time from a glass container. The first date drawn was assigned lottery number 1, the next date number 2, and so on until all dates had been assigned a unique number from 1 to 366 — that number, tied to one’s birthday, was the draft lottery number for that registrant [3] [4] [6].
2. What the numbers meant in practice: who got called first
A registrant’s assigned number determined order of call: lower numbers were called before higher numbers, and the Selective Service published tables showing which lottery numbers had been called (the Administrative Processing Number, or APN, denotes the highest lottery number called for a table year). For the 1970 tables the APN for physical examination calls reached as high as 215, and the last draft calls in the Vietnam era occurred in December 1972 [1] [4].
3. Why the government changed to a lottery system
Before 1969 the draft generally called older registrants first; critics argued that system favored people who could obtain student or occupational deferments and thus was socioeconomically biased. The Nixon administration and Congress moved to a calendar‑date lottery meant to introduce a random element and reduce perceived unfairness by assigning risk by birth date, not by social status [3] [7].
4. The televised drawing and public reaction
The December 1, 1969 drawing was held at Selective Service headquarters and broadcast live; young men listened anxiously because their birthday’s lottery number could mean immediate induction or relative safety for that year. The lottery intensified public debate about fairness and fueled anti‑war sentiment among those who believed the system still worked against the poor and less educated [8] [3].
5. Evidence and claims that the drawing wasn’t truly random
Statisticians and at least one legal challenge argued the 1969 drawing showed nonrandom patterns — notably, later calendar dates were overrepresented among low numbers — likely due to inadequate mixing of capsules or procedural flaws. Critics said a truly random method (e.g., using random number tables or computer permutations) would have avoided those biases [5] [9] [10].
6. How the government responded and later lotteries
After the initial lottery, the Selective Service and outside agencies sought more rigorous methods for subsequent drawings: the 1970 lottery for 1951 births used random permutations prepared by the National Bureau of Standards, and drawings continued in 1970–72 (p1_s1; [3] [second snippet]; p1_s8). Nonetheless, concerns about randomness and fairness persisted in public and academic commentary [11].
7. Practical limits and who actually served
Even with lottery numbers set, many registrants avoided induction through deferments (education, medical), enlistment in alternatives like the National Guard, or evasion; some sources estimate large numbers sought ways to avoid service. The lottery determined order of call but did not guarantee that every low‑number registrant would be inducted — classification and availability mattered, and final call ranges (APNs) varied by year [1] [10] [12].
8. Takeaway and open questions in the record
The Selective Service’s lottery changed the mechanism for ordering calls by tying each man to a lottery number based on his birthday, with lower numbers called first [2] [1]. Available sources document both the physical draw and subsequent statistical critiques; they do not, however, provide exhaustive operational details of every procedural step taken to ensure randomness in each drawing — for those specifics, the archival Selective Service reports and the National Bureau of Standards materials cited for the 1970 permutation work are the next primary documents to consult [3] [4].
If you want, I can: (A) show the 1969 table so you can look up a birthday’s number, or (B) summarize the statistical analyses that demonstrated nonrandomness with charts and p‑values drawn from the academic critiques cited above [5] [9]. Which would you prefer?