At the time of the Vietnam Conflict, as it was called at the time, there was yet the Draft in the U.S., which was not abolished until 1973. At age eighteen, young men were (and still are) required to register under the military Selective Service Act. Also, there were deferments and a lottery in the United States. Some of the deferments included college and graduate school full-time enrollment, employment in an industry necessary to defense, health and mental exceptionalities, being the sole surving child; in addition, as a member of the National Guard, men also did not normally have to serve in Vietnam.
As the war continued, a draft lottery was held on December 1, 1969, in Washington, D.C. This lottery assigned random numbers to registered eighteen-year-olds, and it set the "order of call" for all men of draft age, born in the years 1944-1950. Those with high numbers, therefore, were called to duty. Nearly 850,000 men were affected by the 1969 by this draft lottery.
There are many tragic statistics regarding this involvement of the United States in a Vietnam civil war. Two of these are that 18,000 eighteen-year-olds were dead within two weeks, and nearly 56,000 men died.