By Catharine Arnold (Summary Article)

In the final months of World War I, as the world prepared to exhale after years of unimaginable suffering, an invisible enemy emerged—silent, swift, and utterly lethal. The 1918 influenza pandemic, often called the “Spanish Flu,” claimed more lives than the war itself. Over the course of a single year, it infected an estimated 500 million people worldwide—around one-third of the global population—and killed at least 50 million, possibly as many as 100 million. This article, drawing on Pandemic 1918 by Catharine Arnold, explores how the pandemic unfolded and how it reshaped the world forever.

An Unseen Enemy Emerges

The exact origins of the 1918 flu remain disputed, but many historians believe it began in the United States, possibly at Camp Funston in Kansas. From the cramped conditions of military camps, the virus rapidly spread via troop movements across Europe and the rest of the world. By spring 1918, the virus had reached multiple continents, and by the fall, it had mutated into a far deadlier strain.

Unlike most influenzas, which target the very young and the elderly, the 1918 virus took a devastating toll on young adults aged 20 to 40—those in the prime of life. Entire families were wiped out within days, and communities were devastated by the sheer speed of the outbreak.

The Spanish Flu: A Misnomer

Despite its name, the pandemic did not originate in Spain. Spain, which remained neutral during World War I, had a free press, unlike the Allied and Central Powers, which censored news that could demoralize troops or the public. Spanish newspapers openly reported the flu’s toll, leading the public to believe Spain was the epicenter. In truth, the virus was already circulating elsewhere, but wartime censorship allowed it to spread silently and swiftly. shutdown123