The young men who rode for the Pony Express embodied the adventurous spirit that characterized the United States in the 1850s and '60s. Americans were restless, daring, and willing to risk their safety and comfort in a quest for a better life. The civilized East still pleased some, but thousands more moved westward to satisfy their hunger for open spaces, independence, and prosperity.

Pony Express couriers who raced to and fro across the country between the Missouri River and the Pacific Ocean captured the public's admiration as they expressed its restlessness and daring. Their popularity can be judged by the numerous stories and anecdotes —true accounts, exaggerated reports, and even tall tales—that chronicle their adventures. Today, sorting fact from fiction is often impossible. There is no doubt, however, that these young men were seen as heroes, representing all that was...