The flu spread rapidly during the spring of 1918, infecting far more people than influenza typically would at that time of year. The next wave of infections began in September 1918 and had a disproportionately high impact on young and otherwise healthy people. The pandemic came to be known as the Spanish flu not because of its origin; Spain’s neutrality in World War I left it lacking a censor to silence reporting on the outbreak, making Spanish newspapers the first to carry news of the deadly flu.
On September 28, 1918, Philadelphia held the fourth annual Liberty Loan Drive parade to encourage citizens to financially support the Allied war effort by buying government bonds. Two hundred thousand people attended the parade, ready to support the war with their wallets or perhaps just to witness the spectacle. Seventy-two hours later, all thirty-one hospitals in the city were full. The Catholic Church scrambled to create makeshift hospitals, but most infected patients returned home to crowded working-class neighborhoods to cough and die. A week later 2,600 were dead. Two weeks later, the number was 4,500. In Washington, DC, commissioner Louis Brownlow and his Board of Health hijacked two train cars of coffins headed to Pittsburgh and mandated that they be sent to DC hospitals under armed guard. On October 5 the Philadelphia Inquirer urged people to “talk of cheerful things instead of disease.” By the second week of October, death rates in Philadelphia had hit a thousand per day; steam shovels began to dig mass graves when the city could not keep up with the corpses.
In American Samoa, however, nobody died from the pandemic. Thanks to swift action from the governor, the local population was able to avoid the 1918 flu entirely.
That wasn’t true of Western Samoa, which was about forty miles west from American Samoa and consisted of two large islands, Upolu and Savai’i. Although the populations of both states were culturally the same, sharing a language, culture, and sometimes family ties, the lives of those on each island remained distinct because of colonialism. Western Samoa had been administered by New Zealand since the beginning of World War I. It didn’t shut out the world—and it was devastated by the pandemic. A fifth of the population perished.
The two divergent responses to the flu offer as good of a natural experiment as we are ever likely to see when it comes to whole-country quarantines during pandemics. American Samoa shut out the world and had zero deaths, while at least 8,500 died in Western Samoa. It seems a fairly clear statistical endorsement of quarantine.