During the Great Smallpox epidemic in 1837, 15.000 thousand Native Americans died. It is believed that this disease emerged in human populations about 10.000 BC.
The earliest evidence of smallpox existence was found in Egyptian mummies who died 3.000 years ago. During 18th century, 400.000 people died from smallpox, and in 20th century 500.000, till year 1967 when the number was only two million people. Today, this disease is completely eradicated.