The Pony Express was a rapid mail delivery system started by William Russell, Alexander Majors, and William Waddell in April 1860 The goal was to get mail all the way out to the far west as quickly as possible. Indeed, it took about 10 days to get from St Joe to Sacramento rather than the months of previous methods. Its most famous rider (although he probably never really rode for them) was Buffalo Bill Cody, who, by putting it into his Wild West shows, surely kept its memory alive.

There was an ad (which probably never actually ran) that encapsulated all that magic:

"WANTED YOUNG SKINNY WIRY FELLOWS Not over eighteen. Must be expert riders willing to risk death daily. Orphans preferred. Wages $25 per week. Apply Central Overland Express."

These fellows raced along the route, travelling light on great horses that they changed at way-stations every 10-12 miles.

The Civil War soon put a big dent in operations but its true killer was, of course, the transcontinental telegraph, completed in October 1861. The service closed in that same month, having never made money but having made history. The real, bottom line facts about the Pony Express -- there are few or none. We no longer know what is legend and what is real, save that it existed for about 18 months.

More Info: en.wikipedia.org