Because the Vietnam War was primarily a ground war, 82 percent of American servicemen who fought in Vietnam were members of the Army and the Marines, and two-thirds of those soldiers were drafted. If you wanted to avoid being drafted as an infantryman on the front lines, one strategy was to enlist in another branch of the military.

“Draft-motivated enlistment was a way of exerting some choice into the process,” says Rutenberg. “That’s why a lot of people looking to avoid service in Vietnam tried to join the ROTC or the National Guard if they could, because they knew they most likely wouldn't be going.”

The Air Force, Navy and Coast Guard had higher enlistment standards, but acceptance into one of those other branches also greatly decreased a young man’s odds of being shipped off to Vietnam.

Before the Vietnam era, the only Americans who qualified for conscientious objector status were members of pacifist religious sects like Quakers, Amish, Mennonites and Jehovah’s Witnesses. In both World Wars and the Korean War, men who qualified as conscientious objectors were given alternative service assignments at home or abroad, and some served with great distinction.

Still, the only way to receive a conscientious objector deferment was on religious grounds. A moral or ethical opposition to war didn’t cut it. That changed with the landmark 1970 Supreme Court decision in Welsh v. United States, in which the justices expanded the definition of conscientious objector to include anyone who’s opposition to war is sufficiently “religious” without necessarily professing a belief in God.

“By 1971, you could get a conscientious objector deferment legally if you were morally opposed to war,” says Rutenberg. “It didn’t have anything to do with religion.”

A total of 170,000 men received conscientious objector deferments during the Vietnam War—61,000 in 1971 alone. Many of them received assistance from “draft counseling” organizations like the American Friends Service Committee (Quakers) and the Central Committee for Conscientious Objectors (CCCO).

As mentioned earlier, married men were exempted from the draft until August 26, 1965. After that, the only way for a married man to earn a deferment was to have a child. But even those rules changed over the course of the Vietnam War.

Back in 1963, President John F. Kennedy signed an executive order that automatically qualified men with children for a “hardship deferment” (III-A) from the draft. This motivated millions of “Kennedy fathers,” as they were known, to opt for fatherhood even before troops were being sent to Vietnam.

After 1965, when marriage alone could no longer save men from the draft, there was another explosion in American fertility. According to a demographic study, birth rates were 13 percent higher in 1970 than they were before the Vietnam era. When the draft lottery was first held in 1969, women whose husbands had high-risk draft numbers were 40 percent more likely to get pregnant than women whose spouses had a low risk of being drafted.

In 1970, President Richard Nixon changed the law yet again. Men with children were no longer “automatically” deferred. They now had to prove that their absence would be a financial hardship to their dependents. Following the announcement, birth rates among young couples sharply declined.

For most of the Vietnam War, full-time college students and graduate students were able to get a legal deferment from the draft. Since college was expensive, and Black and minority college enrollment was low at the time, this is one of the loopholes that unevenly benefited middle- and upper-class white Americans.

“One of the points that’s very clear is that men with means—whether that's actually money, cultural or political capital, or a better education—absolutely could get out of service a lot easier than folks without those things,” says Rutenberg. “Poor and working-class men, particularly men of color, were disproportionately drafted.”

Similar to the effect on marriage and birth rates, there was a 4- to 6-percent increase in college attendance during the late 1960s, when college students were automatically deferred. In 1971, most of the college and graduate student deferments were dropped except for divinity students and medical students.

A physical exam was required as part of induction into military service. The standard exam was a cursory once-over by a military doctor who was looking for obvious physical limitations or conditions.

Another way to earn a 4-F deferment (“unfit for service”) was to convince a friendly doctor to exaggerate or invent a condition disqualifying an otherwise healthy young man from service. This is yet another way that wealthier and better-connected Americans had an advantage when it came to avoiding the draft.

Politicians have come under fire for their use of medical deferments to stay out of the Vietnam War. Both Donald Trump and Joe Biden avoided the draft through a combination of student deferments and medical exemptions (“bone spurs” for Trump and “asthma” for Biden).

Even though the U.S. military barred gay men from serving during Vietnam, it wasn’t an automatic disqualifier for a registrant to respond “yes” to a question about “homosexual tendencies.” The decision was left to the local Selective Service Board, and when demand for recruits was high, the issue was sometimes overlooked.

As the Vietnam War dragged on, it grew increasingly unpopular with the American public, especially young people. Instead of quietly avoiding the draft through deferments and exemptions, some draft-eligible men chose open resistance and protest. One of the strongest anti-war statements was to publicly burn your draft card.

Rutenberg says that the number of people who actually burned their draft card was relatively low, but they got a lot of news coverage. Other ways of protesting the draft and the war itself was to return your draft card to the Selective Service Board, fail to show up for your pre-induction physical, or refuse to step forward during the induction ceremony to affirm that you’re joining.

Failure to comply with Selective Service requirements was a criminal offense enforced by the Department of Justice. But Rutenberg says that by the 1970s, the DOJ was so overwhelmed by non-compliance that it only prosecuted the most egregious and public cases.

Approximately 570,000 men were classified as “draft offenders” during the Vietnam War, but only 8,750 were convicted and 3,250 were imprisoned.

Everything changed with the introduction of the draft lottery in 1969, says Rutenberg. Instead of drafting recruits from oldest to youngest—starting with 26-year-olds and moving down to 18-year-olds—the lottery selected from a smaller pool of people turning 20 during that calendar year. In a televised drawing, birth dates were randomly selected and placed in order from 1 through 365.

People with lower numbers were almost guaranteed to be drafted, higher numbers breathed a sigh of relief, and “the people in the middle scrambled to find a way out,” says Rutenberg, maybe through a conscientious objector deferment, a student deferment or a medical exemption.

For tens of thousands of American men without options for deferment, the safest bet was to leave the country. The total number of men who fled the country to avoid the Vietnam draft is hard to quantify but estimates range from 40,000 to as many as 100,000. The most popular destinations were Canada and Sweden, and many never returned.

Nixon ended the draft in 1973, and President Jimmy Carter issued a blanket pardon in 1977 for all nonviolent breaches of the Selective Service Act.