Spanish Flu is a disease that first appeared after World War 1 (1918). The exact origin of Spanish Flu is still not clear. It seems to be originated from the U.S. It was the most massive epidemic of the twentieth century, 50 million people died worldwide, and the estimated number of cases is 500 million. Symptoms of Spanish Flu are: becoming lethargic, having fever, and the body was aching. Spanish Flu lasted from 1918 to 1920, governments used similar techniques with the one they are now using for COVID19 to flatten the curve. The virus spread through the spit, so the usage of masks was essential to flatten the curve.