When Paul Bailey was born at Beaver County Hospital in Milford, Utah on May 9, 1955, it took less than two hours for the staff to give him a tattoo. Located on his torso under his left arm, the tiny marking was rendered in indelible ink with a needle gun and indicated Bailey’s blood type: O-Positive.

“It is believed to be the youngest baby ever to have his blood type tattooed on his chest,” reported the Beaver County News, cooly referring to the infant as an “it.” A hospital employee was quick to note parental consent had been obtained first.

The permanent tattooing of a child who was only hours old was not met with any hysteria. Just the opposite: In parts of Utah and Indiana, local health officials had long been hard at work instituting a program that would facilitate potentially life-saving blood transfusions in the event of a nuclear attack. By branding children and adults alike with their blood type, donors could be immediately identified and used as “walking blood banks” for the critically injured.

Taken out of context, it seems unimaginable. But in the 1950s, when the Cold War was at its apex and atomic warfare appeared not only possible but likely, children willingly lined up at schools to perform their civic duty. They raised their arm, gritted their teeth, and held still while the tattoo needle began piercing their flesh.

The practice of subjecting children to tattoos for blood-typing has appropriately morbid roots. Testifying at the Nuremberg Tribunal on War Crimes in the 1940s, American Medical Association physician Andrew Ivy observed that members of the Nazi Waffen-SS carried body markings indicating their blood type [PDF]. When he returned to his hometown of Chicago, Ivy carried with him a solution for quickly identifying blood donors—a growing concern due to the outbreak of the Korean War in 1950. The conflict was depleting blood banks of inventory, and it was clear that reserves would be necessary.

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If the Soviet Union targeted areas of the United States for destruction, it would be vital to have a protocol for blood transfusions to treat radiation poisoning. Matches would need to be found quickly. (Transfusions depend on matching blood to avoid the adverse reactions that come from mixing different types. When a person receives blood different from their own, the body will create antibodies to destroy the red blood cells.)

In 1950, the Department of Defense placed the American Red Cross in charge of blood donor banks for the armed forces. In 1952, the Red Cross was the coordinating agency [PDF] for obtaining blood from civilians for the National Blood Program, which was meant to replenish donor supply during wartime. Those were both measures for soldiers. Meanwhile, local medical societies were left to determine how best to prepare their civilian communities for a nuclear event and its aftermath.

As part of the Chicago Medical Civil Defense Committee, Ivy promoted the use of the tattoos, declaring them as painless as a vaccination. Residents would get blood-typed by having their finger pricked and a tiny droplet smeared on a card. From there, they would be tattooed with the ABO blood group and Rhesus factor (or Rh factor), which denotes whether or not a person has a certain type of blood protein present.

The Chicago Medical Society and the Board of Health endorsed the program and citizens voiced a measure of support for it. One letter to the editor of The Plainfield Courier-News in New Jersey speculated it might even be a good idea to tattoo Social Security numbers on people's bodies to make identification easier.

Despite such marked enthusiasm, the project never entered into a pilot testing stage in Chicago.

Officials with the Lake County Medical Society in nearby Lake County, Indiana were more receptive to the idea. In the spring of 1951, 5000 residents were blood-typed using the card method. But, officials cautioned, the cards could be lost in the chaos of war or even the relative quiet of everyday life. Tattoos and dog tags were encouraged instead. When 1000 people lined up for blood-typing at a county fair, two-thirds agreed to be tattooed as part of what the county had dubbed "Operation Tat-Type." By December 1951, 15,000 Lake County residents had been blood-typed. Roughly 60 percent opted for a permanent marking.

The program was so well-received that the Lake County Medical Society quickly moved toward making children into mobile blood bags. In January 1952, five elementary schools in Hobart, Indiana enrolled in the pilot testing stage. Children were sent home with permission slips explaining the effort. If parents consented, students would line up on appointed tattoo days to get their blood typed with a finger prick. From there, they’d file into a room—often the school library—set up with makeshift curtains behind which they could hear a curious buzzing noise.

When a child stepped inside, they were greeted by a school administrator armed with indelible ink and wielding a Burgess Vibrotool, a medical tattoo gun featuring 30 to 50 needles. The child would raise their left arm to expose their torso (since arms and legs might be blown off in an attack) and were told the process would only take seconds.

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Some children were stoic. Some cried before, during, or after. One 11-year-old recounting her experience with the program said a classmate emerged from the session and promptly fainted. All were left with a tattoo less than an inch in diameter on their left side, intentionally pale so it would be as unobtrusive as possible.

At the same time that grade schoolers—and subsequently high school students—were being imprinted in Indiana, kids in Cache and Rich counties in Utah were also submitting to the program, despite potential religious obstacles for the region's substantial Mormon population. In fact, Bruce McConkie, a representative of the Church of Jesus Christ of Latter-Day Saints, declared that blood-type tattoos were exempt from the typical prohibitions on Mormons defacing their bodies, giving the program a boost among the devout. The experiment would not last much longer, though.

By 1955, 60,000 adults and children had gotten tattooed with their blood types in Lake County. In Milford, health officials persisted in promoting the program widely, offering the tattoos for free during routine vaccination appointments. But despite the cooperation exhibited by communities in Indiana and Utah, the programs never spread beyond their borders.

The Korean conflict had come to an end in 1953, reducing the strain put on blood supplies and along with it, the need for citizens to double as walking blood banks. More importantly, outside of the program's avid boosters, most physicians were extremely reticent to rely solely on a tattoo for blood-typing. They preferred to do their own testing to make certain a donor was a match with a patient.

There were other logistical challenges that made the program less than useful. The climate of a post-nuclear landscape meant that bodies might be charred, burning off tattoos and rendering the entire operation largely pointless. With the Soviet Union’s growing nuclear arsenal—1600 warheads were ready to take to the skies by 1960—the idea of civic defense became outmoded. Ducking and covering under desks, which might have shielded some from the immediate effects of a nuclear blast, would be meaningless in the face of such mass destruction.

Programs like tat-typing eventually fell out of favor, yet tens of thousands of adults consented to participate even after the flaws in the program were publicized, and a portion allowed their young children to be marked, too. Their motivation? According to Carol Fischler, who spoke with the podcast 99% Invisible about being tattooed as a young girl in Indiana, the paranoia over the Cold War in the 1950s drowned out any thought of the practice being outrageous or harmful. Kids wanted to do their part. Many nervously bit their lip but still lined up with the attitude that the tattoo was part of being a proud American.

Perhaps equally important, children who complained of the tattoo leaving them particularly sore received another benefit: They got the rest of the afternoon off.