evidence: In 1918 a pandemic influenza killed an estimated 50 million people across the globe, or 3 percent of the world’s population. This estimate is conservative and likely low, as worldwide systems to track civilian deaths were not in place. The first cases presented in January of 1918, and the last were in 1920. Most deaths occurred in the fall of 1918, with another outbreak in the spring of 1919. This was not the first time a wave of influenza had passed across the world, but it was by far the worst. This pandemic has been referred to as the Spanish flu. That name is misleading. Spain was neutral in World War I, so the Spanish press was left free to publish information about the spread of the disease, and thus the initial news about the pandemic came from Spanish sources. There are many hypotheses about where this strain of influenza originated, but none of them center on Spain. It might have begun in the Midwest United States, where there were widespread contemporaneous cases of influenza in pig livestock. Wherever it began, its impact was worldwide, and the transport of large numbers of servicemen certainly exacerbated the situation.