John Wesley Powell always had the spirit of adventure in him. As a young man, he traveled all over the United States exploring. When the Civil War began, Powell went to fight for the Union, and even after he lost most of his right arm, he continued to fight until the war was over. In 1869, he embarked with the Colorado River Exploring Expedition-- ten men in four boats-- to float through the Grand Canyon. Ten explorers went in, but only six came out....