The end of a scourge

"The prayer that has been mine for twenty years, that I might be permitted in some way or some time to do something to alleviate human suffering, has been answered "
--Major Walter Reed, writing to his wife, New Year's Eve, 1900

As he wrote to his wife of his stunning success in the mission to identify the cause of yellow fever and find a way to eradicate the disease, Walter Reed had answered the prayers of millions. For more than 250 years, the yellow jack had ravaged the Americas, bringing death to millions and striking panic in entire...