The U.S. Has Had ‘Vaccine Passports’ Before—And They Worked

A southbound passenger train halted in southern Quebec near the Vermont border, where an elderly, bespectacled man boarded the train. This man, a physician named Dr. Hamilton, worked his way down the aisles, asking each passenger, “Been vaccinated?” Unless they had documentation proving that they had been, Hamilton asked them to display their arms, where he looked for a “fresh scar” indicating a recent inoculation. If he could find no scar, a local paper informed readers, he either vaccinated the passenger on the spot or asked them to leave the train before it entered the United States.

The year was 1885. U.S. border officials in the late 19th century did not expect travelers to carry the identification documents that international transit requires today—but they did often require passengers to provide evidence that they had been vaccinated from smallpox. Whether at ports of entry including New York’s Ellis Island and San Francisco’s Angel Island, or along the U.S. border with Canada or Mexico, officials expected border-crossers to prove their immunity. As an El Paso newspaper put it in 1910, travelers needed to show one of three things: “A vaccination certificate, a properly scarred arm, or a pitted face” indicating that they had survived smallpox.

Today, as Americans have begun to look ahead to life after the COVID-19 pandemic, some have argued that a printed or electronic certification of a person’s vaccination status, often referred to as a vaccine passport, would allow a safe return to communal life. A few major sports arenas have already announced that they will only allow fans to attend games with proof of vaccination. Many are also speculating that proof of vaccination will be necessary for international travel this summer. Detractors claim that requiring such documentation infringes on individual liberties. Some even suggest that these passports could be the beginning of a slippery slope toward “1940s Nazi Germany” or a surveillance state. Florida Governor Ron De Santis has announced a blanket ban on all vaccine passports, calling it “unacceptable for either the government or the private sector” to require vaccination in order for citizens to be “able to participate in normal society.”

But this would not be American history’s first example of a vaccine passport—and in fact, Americans’ long campaign against smallpox shows that the benefits of such a system can extend far beyond the venues into which such a passport would grant admission.

Get your history fix in one place: sign up for the weekly TIME History newsletter

Introduced to the western world in the 18th century, the smallpox vaccine was the first of its kind. It was administered not with a syringe but by scratching pustular material on a person’s arm. Typically, the vaccinated area would form a blister, scab over, and leave behind a distinctive scar. Because of its unique appearance, Americans treated the smallpox scar as a documentation of vaccination, or a sort of early vaccine passport. Toward the end of the Civil War, a smallpox outbreak in Tennessee led Union Brigadier General Ralph Pomeroy Buckland to order that physicians inspect everyone in Memphis and vaccinate “all found without well marked scars.”

By the late 19th century, American public health professionals pushed for an even more aggressive approach to vaccination. During another smallpox outbreak in Tennessee, in 1882 to 1883, for example, a Memphis newspaper reported, “At Chattanooga, when a doctor and a policeman enter a house together the folks inside know that they have to show a scar, be vaccinated, or answer to the law. There is no nonsense in that way of stamping out disease and saving life.”

During a series of smallpox outbreaks across the United States from 1898 through 1903, many states authorized compulsory vaccination, while other leaders sought to use the power of public and private institutions to pressure reluctant Americans to accept the vaccine. A Chicago physician wrote in 1901 that “Vaccination should be the seal on the passport of entrance to the public schools, to the voters’ booth, to the box of the juryman, and to every position of duty, privilege, profit or honor in the gift of either the State or the Nation.”

Employers across the country acted to make smallpox immunity a condition of employment. Factories, mines, railroads and other industrial workplaces with tight quarters were particularly forceful in demanding proof of vaccination. In 1903, Maine’s government decreed that “no person be allowed to enter the employ of, or work in, a lumber camp who can not show a good vaccination scar. Though workers sometimes resisted, corporations and governments usually ensured that they took the vaccine in the end.

Social gatherings and clubs, too, sometimes required proof of vaccination in order to attend. When smallpox swept through Kansas City in 1921, one newspaper reported that “‘Show a scar’ has been officially adopted as the passwords to lodges and other meetings.” Public school leaders across the country also required students to present a “plain scar, the records of a school or a certificate by a reputable physician” in order to enter their institutions. Among others, the superintendent of the Savannah, Ga., school system in 1897 arranged for students to be provided with “admission cards” to their school once they provided proof of vaccination.

Read more: The history of vaccines, from smallpox to COVID-19

Some Americans resisted these public health measures. The predecessors of today’s anti-vaxxers questioned the vaccine’s effectiveness or falsely claimed that it caused smallpox or other side effects. One Illinois writer dramatically claimed in 1923 that “A scar from forced vaccination is a brand, a mark of medical tyranny and despotism.” Newspapers brimmed with rumors about young women who tried to avoid vaccination to avoid blemishing their arms with the ugly scar.

Much of the American public viewed this hesitancy as a relic of a bygone, unenlightened age. In 1893, a Raleigh newspaper carried an account of an elderly man recalling with undisguised scorn the anti-vaxxers of earlier decades who believed that childhood vaccines would lead young people to develop “bovine propensities.” Some, he remembered, regarded a vaccination scar as the “mark of the beast” referenced in the Bible’s Book of Revelations. (Today, misinformation concerning the new COVID-19 vaccines has led many Americans to the same sort of confusion that Americans felt concerning early smallpox vaccines. Indeed, U.S. Representative Marjorie Taylor Greene recently referred to proposed vaccine passports as “Biden’s mark of the beast.”)

And despite any backlash, stringent enforcement of smallpox vaccination requirements successfully pressured vaccine-hesitant populations to accept them. Though some groups continued to resist these public health campaigns, far more Americans acquiesced to vaccination rather than endanger their employment, mobility or their children’s education.

After decades of widespread vaccination, the United States effectively eradicated smallpox within its borders by the middle of the 20th century.

That the United States practiced aggressive, and even compulsory, vaccination campaigns at the turn of the 20th century may surprise Americans today. These actions were possible in part because they took place in an age of progressive experimentation in government policy—a time, as historian Michael Willrich notes in his book Pox, when Americans were beginning to conceive of liberty not only as freedom from government regulation, but also as freedom to meaningfully and actively participate in public life. Vaccination requirements involved some limitations on individual behavior, but they also made it easier for communities to forego complete quarantines and to thrive. They also set a precedent that schoolchildren still benefit from, as every American state now requires that most students be vaccinated against diseases such as measles, polio and pertussis. Americans today have inherited the widespread smallpox-era consensus that some “vaccine passports,” by another name, are necessary.

Unlike the smallpox vaccines of the past, COVID-19 vaccines leave no visible marks. In one sense, this is helpful as it prevents one strain of earlier vaccine hesitancy from returning. But the absence of scarring also renders vaccination invisible and uncertain, making it almost impossible for us to know who is immune and who remains vulnerable. Ensuring that a person’s vaccination status can be verifiable and visible through documentation would be an important tool for lifting quarantines and defeating COVID-19. Like the scars of the past, vaccine passports could help Americans to finally bring this pandemic to an end.

Historians’ perspectives on how the past informs the present

Jordan E. Taylor teaches history at Smith College