Both on the home front and in the combat zones of 1918, the greatest single killer of the Great War was not artillery, machine guns, or poison gas: it was far more insidious and invisible. By some estimates, half of the doughboys, Marines and sailors who died in Europe fell not to enemy fire but to the influenza pandemic of 1918-1920. Sometimes referred to as the Spanish flu, the “plague of the Spanish lady,” and the “grippe,” the epidemic disappeared as quickly as it had appeared by the time the Armistice was signed in November 1918.
On March 11, 1918 the first cases of what would become the influenza pandemic were reported in the U.S. when 107 soldiers rapidly became ill at the Camp Funston training camp in Fort Riley, Kansas. It was the worst pandemic in modern history. The flu that year killed only 2.5 percent of its victims, but more than a fifth of the world’s entire population caught it; it is estimated that between fifty million and one hundred million people died in just a few months. Historians believe at least 500,000 died in the United States alone.
The influenza outbreak swept through military bases in the United States. The virus was an exceptionally deadly strain that struck young, previously healthy adults particularly hard. Once their bodies were weakened, many were vulnerable to secondary infections such as pneumonia, often leading to death. By the late spring, there were influenza outbreaks in fourteen of the largest Army training camps in the United States. After temporarily subsiding, a second more deadly wave of influenza appeared in late summer 1918. By mid-September, it had developed into a mass outbreak. Many servicemen caught the influenza virus in the United States and boarded troopships bound for Europe, unaware of their infected condition. Crowded quarters on the ships provided an ideal environment that readily enabled the flu to spread. Some soldiers did not survive the two-week voyage. Others fell sick during the crossing and were taken directly to hospitals in Britain and France when their vessels entered port.
Healthy soldiers arriving in France in late 1917 and in early 1918 immediately went into battle, distinguishing themselves in infantry charges, artillery exchanges, and trench warfare. However, if they were not already infected by the virus, many contracted it in the close quarters in which they were confined. As has been pointed out, others contracted the disease onboard ship before even arriving in England or France. A third group became ill so quickly in the U.S. that they never had time to go overseas. They died in the field hospitals of their training camps. Others were buried at sea before even reaching land.
