The first quarantine was passed into law in the port city of Ragusa (today’s Dubrovnik) on July 27, 1377, during the Bubonic Plague, or Black Death. It stipulated: “Those who come from plague-infested areas shall not enter [Ragusa] or its district unless they spend a month on the islet of Mrkan or in the town of Cavtat, for the purpose of disinfection.” Doctors at the time observed that the spread of the Black Death could be slowed by isolating individuals.

Quarantine played a large role in how 20th-century American cities responded to the outbreak of the 1918 influenza pandemic, or Spanish flu, following the return of soldiers from World War I. In San Francisco, naval arrivals were quarantined before entering the city. In San Francisco and St. Louis, social gatherings were banned and theaters and schools were closed. Philadelphia became a test case in what not to do when, 72 hours after holding the ill-fated Liberty Loan parade in September, the city’s 31 hospitals were at capacity following the superspreader event.

Doctors treating patients during the plague wore masks with long, bird-like beaks. They had the right idea—the long beaks created social distance between patient and doctor and at least partially covered their mouth and nose—but the wrong science. Doctors at the time believed in Miasma theory, which held that diseases spread through bad smells in the air. The beaks were often packed with strongly scented herbs believed to ward off illness.

During the 1918 influenza pandemic, masks became the go-to means of stopping the spread of infection to the public. Masks became mandatory in San Francisco in September of 1918, and those who didn’t comply faced fines, imprisonment and the threat of having their names printed in newspapers as “mask slackers.”

But newspapers weren’t just for shaming; they also printed instructions on how to make masks at home. People even got creative with masks, with the Seattle Daily Times running an article entitled “Influenza Veils Set New Fashion” in October of 1918.

Washing your hands to reduce the spread of disease is an accepted part of hygiene now, but frequent hand washing was a bit of a novelty during the early 20th century. To encourage the practice, "powder rooms," or ground-floor bathrooms, were first installed as a way to protect families from germs brought in by guests and ubiquitous delivery people dropping off goods like coal, milk and ice.

Previously, these visitors would have traveled through the home to use the bathroom, tracking outside germs with them. (Typhoid Mary infamously spread the disease from which she earns her nickname by not properly washing her hands before handling food.)

Germ theory was a relatively new concept brought to light in the mid-1800s by Louis Pasteur, Joseph Lister, and Robert Koch that held that disease was caused by microorganisms invisible to the naked eye. Having a sink on the ground floor made it easier to wash your hands upon returning home.

Speaking of health and design, there’s a reason why hospitals, subways and 1920s bathrooms were often tiled in pristine white: White tiles are easy to clean and make any dirt or grime highly visible.

While the topic of whether or not to return to in-person schooling is a complex one in a pandemic, the 2019-20 coronavirus pandemic was not the first time that universities and schools were forced to grapple with the question.

In 1665, a young Isaac Newton was sent home from Cambridge University to his family's farm following an outbreak of bubonic plague. It was on that farm that he allegedly witnessed the falling apple that led to his law of universal gravitation.

While fresh air doesn’t always lead to fresh ideas, it was used to help contain the Tuberculosis outbreak in the early 1900s that claimed 450 American lives a day—many of them children. Germany pioneered the concept of open-air schools, and by 1918, over 130 American cities had them. The movement toward fresh air also inspired city planners to create more green spaces to promote public health.

During the second wave of the Spanish flu outbreak in the fall of 1918, public schools in Chicago and New York stayed open. At the time, New York City’s health commissioner told the New York Times: “[Children] leave their often unsanitary homes for large, clean, airy school buildings, where there is always a system of inspection and examination enforced.”