WorldSmallpox killed untold millions during Spanish ​conquest; now researchers have obtained direct molecular evidence of smallpox carried to the New World. But the biggest blow they delivered came from something else entirely - smallpox and other infectious diseases that ravaged indigenous populations. They recovered ancient viral DNA from the mummies of two people who died during the early Spanish colonial period in an Inca community in northern Chile. In the Americas, smallpox and other viral diseases killed, according to some estimates, roughly 90% of the indigenous people. In addition to killing millions, smallpox delivered a psychological blow.