Context
Back in the mid-1800s, the United States were hardly united. There was barely anything west of the Appalachian mountains, and Americans couldn't figure out what to do with the Louisiana purchase.
Then came the frontier. The wild west was exactly that, and despite the gold rush, less than a million people ventured out into the wilderness. This is because the west was completely isolated from the mainland United States.
Remember, this was before the telegraph - the slightest of information had to move physically across the vast expanse of North America. And as we know, information is everything. To get to California, people had to sail on a ship to Panama, cross the land (there was no Panama Canal) and then set sail to the West. It took an over a month just to get the simplest message across. Indeed, there was far more communication between New York and London than New York and San Francisco.
The US Postal Service invested heavily in making railroads up to Missouri, but no one would dare make the incredibly arduous journey across the frontier. Enter, the Pony Express!
A bold new plan
The California gold rush proved immensely profitable and there was great demand for faster methods of communication. Gold diggers and other merchants were ready to shell out big money to get their mails delivered faster.
In the late 1850s, three enterprising businessmen - William Russell, Alexander Majors, and William Waddell - came up with an outrageous plan to connect St Joseph, Missouri to Sacrmento, California. The goal was to cut down the mailing time from San Francisco to New York by an incredible 70% - making it across in just 10 days!
Logistics
At its peak, the Pony Express hired 400 of America's finest horses, with 120 skilled riders to match. 184 stations were erected along the arduous 1,900 mile long route at an average of one station every 10 miles. Remember - these stations were maintained in the middle of nowhere. If the harsh conditions weren't enough, they even had to deal with the Paiute War. Despite this, only one mailing failed to make it to their destination on time!
Each pouch - called mochila - would contain 20 pounds worth of mail. Each horse would thunder across land for between stations - an average of 10 miles - before the rider switches to a different horse. Each rider would ride across 7 to 10 stations, before the mochila would be passed on to the next rider.
It was an extravagant relay of horses and riders which kept the mochilas moving along 24x7. The end goal of 10 days was easily achieved. Indeed, the Pony Express set a record of delivering the news of Lincoln's election from East to West newspapers in just 7 days and 17 hours!
So how much an operation this lavish cost? Over $130 (equivalent) for a single 1/2 ounce letter. But hey, time is money, and businesses paid up! In just 19 months, the Pony Express delivered 35,000 letters.
Civil War and overland telegraph
The Pony Express ran for just 19 months, from April 1860 to October 1861. The Civil War halted operations. Meanwhile, the overland transcontinental telegraph project switched into high gear, perhaps inspired by the demand of Pony Express.
By the time things settled down, the transcontinental telegraph had reached Sacramento, finally connecting the Atlantic and Pacific coasts and making the American states united. The Pony Express was declared defunct just two days later.
Further reading -
http://ponyexpress.org/pony-express-historical-timeline/
https://postalmuseum.si.edu/exhibits/current/pony-express/pony-express-2.html
https://www.fhwa.dot.gov/infrastructure/back0304.cfm
http://about.usps.com/publications/pub100/pub100_013.htm
Wendover productions
http://www.ieeeghn.org/wiki/index.php/Milestones:Transcontinental_Telegraph,_1861
All images from Wikimedia.