Just over one hundred years ago a band of scientists and volunteers from two countries decided to fight against one of the world’s deadliest diseases. Some members of this group came from Cuba; some, from the United States. Unfortunately, today relatively little is known about the Cubans who took part in this important battle, while libraries contain many rich sources of information about the American team. For this reason, I have concentrated on the extremely well documented American part of the story. But readers should remember that without the great Cuban scientific contribution, there might have been no story to tell.