A: The main cause of rapid population growth is when there are more births than there are deaths, which is referred to as a natural increase. Other causes of ... Full Answer >
Spanish flu (1918-1919). The influenza pandemic of 1918-1919 killed more people than the World War I, at somewhere between 20 and 40 million people. It has been cited as the most devastating epidemic in recorded world history. Known as Spanish Flu or La Grippe the influenza of 1918-1920 was a global disaster.
More than 25 percent of the U.S. population became sick, and some 675,000 Americans died during the pandemic. The 1918 flu was first observed in Europe, the U.S. and parts of Asia before swiftly spreading around the world. Surprisingly, many flu victims were young, otherwise healthy adults.