The River of Doubt: Theodore Roosevelt's Darkest Journey

by Candice Millard

Roosevelt was five feet eight inches tall, about average height for an American man in the early twentieth century, weighed more than two hundred pounds, and had a voice that sounded as if he had just taken a sip of helium, but his outsized personality made him unforgettable—and utterly irresistible.

It would be a measure of his profound respect for Rondon that, years later, Roosevelt would count the Brazilian officer among the four greatest explorers of his time—alongside Roald Amundsen, Richard Byrd, and Robert Peary.