people worldwide were estimated to be infected by the influenza virus between 1918 and 1919. It represented about one-third of the planet’s population at the time.
20 - 50 million
people are estimated to have died, making it the deadliest pandemic in modern history.
+ of the U.S. population became sick, and some 675,000 Americans died during the pandemic.
waves in which the disease spread, in each case the mortality rate increased. It came to be known as the Spanish flu because Spain was one the earliest countries to be hit hard by the virus.