The Pony Express carried letters by horseback between St. Joseph, Missouri, and Sacramento from 1860 to 1861.
The service used a relay system of riders and horses across roughly 1,800 miles of frontier territory. Riders changed horses at stations placed about 10 to 15 miles apart, allowing mail to travel much faster than ordinary stagecoach routes.
The route was divided into eastern, central, and western sections, with relay stations in places such as Fort Kearny, Fort Laramie, and Salt Lake City. Young riders carried a lightweight mochila, or mail pouch, that could be transferred quickly between horses.
The service became famous, but it lasted only about 18 months. The completion of the first transcontinental telegraph in October 1861 made rapid written messages far less important. The Pony Express was a commercial venture, not an official U.S. government postal route.