At the turn of the last century, Panama was the most dangerous place in the world. Travelers would endure a voyage of thousands of miles rather than risk a 40-mile train trip across the narrow strip of land. After thousands died in the French attempt to dig a canal across the Isthmus, Theodore Roosevelt decreed "Not one spade of dirt" would be turned until the treacherous, disease-filled jungles were made safe. To that end, a small band of American...