The Pony Express was a swift mail service that was only active from April 1860 to October 1861. It was a crucial communication link between the East Coast and West Coast during a time when communication between Washington, DC, and Sacramento was helping establish California as a free state, as well as helping the Union factions gain strength just prior to the Civil War.
A series of relay stations was established with fresh horses so the rider could get fresh mounts all along the route. The riders simply changed mounts and rode as fast as possible—rarely stopping even to sleep or eat. It took immense courage and perseverance on the part of the riders and the relay station personnel, and the journey took about ten days through rough terrain, Indian massacres, ambushes, and brutal weather conditions over the Sierra.