The 1918 Influenza Pandemic

It was not Spanish; it was called that because wartime Spain was neutral and its press was not censored, so its reports were the ones the world read. It killed more people than the war it followed, and unusually it killed the young and healthy hardest.

On 28 September 1918 Philadelphia held a war-bonds parade for two hundred thousand people against medical advice. Within days the hospitals were full; within a month twelve thousand of its citizens were dead. St Louis cancelled its parade and its death rate was less than half.