"Orphans preferred" was the call that went out to the daring of heart when the Pony Express was organized 150 years ago. Called "The Greatest Enterprise of Modern Times" the endeavor required young men willing to risk life and limb in a relay race that crossed the frontier on a route from St. Joseph, Missouri, to San Francisco, California, speeding the delivery of mail to an astonishing ten days. This popular history, illustrated with contemporary photography and archival images and documents from the past celebrates the sesquecentennial of the start--and end--of those daring rides, which ended with the completion of the transcontinental railroad.