In 1838, the U.S. government launched the largest discovery voyage the Western world had ever seen-6 sailing vessels and 346 men bound for the waters of the Pacific Ocean. Four years later, the U.S. Exploring Expedition returned with an astounding array of accomplishments and discoveries: 87,000 miles logged, 280 Pacific islands surveyed, 4,000 zoological specimens collected, including 2,000 new species, and the discovery of the continent of Antarctica....