1918/1919- The Spanish Flu
The Walter Reed Hospital Flu Ward during the 1918-1919 Spanish Flu, courtesy of Harris & Ewing, via The Library of Congress
The deadliest flu pandemic in history, the 1918-1919 Spanish Flu may have been the deadliest disease in history. In The Great Influenza by John Barry, Barry estimates that the flu killed eight to ten percent of all young adults on the planet, and between 50 and 100 million people in all. And while Gina Kolata, in her book Flu notes that "the flu was expunged from newspapers, magazines, textbooks and society's collective memory," Barry makes the case that investigation into the cause of the Spanish Flu, and treating its victims, significantly influenced the development of modern medicine.