Undaunted Courage: Like Lewis and Clark, John Wesley Powell was entering unknown territory when he undertook an expedition to explore the Colorado territories the last unmapped portion of the United States in 1869. What started as a scientific expedition through uncharted territory turned out to be a harrowing adventure for John Wesley Powell and nine other men. In 1869, John Wesley Powell, who lost his right arm at the Battle of Shiloh during the Civil War, led a team of ten men down the Green and into the Colorado River, then through the Grand Canyon. No one had ever made the trip before. One man left before the trip was well under way; three more climbed out of the Grand Canyon when they came to believe that the chance of emerging from it alive was nonexistent (Those three men were killed by Indians). The trip was the last great expedition into the last unexplored section of the American interior and Powell's book about it has become an American classic. Full of excitement and adventure, the book also contains a clear and detailed geologic and topolgraphic description of the plateau country the two rivers traverse and of the Indian tribes who lived in the area.