April 3, 1860 The 1st successful United States Pony Express run from Saint Joseph, MO to Sacramento
The Pony Express was a mail service delivering messages and mail from St. Joseph, Missouri across the Great Plains, over the Rocky Mountains and the Sierra Nevada to Sacramento, California by horseback, using a series of relay stations. During its 18 months of operation, it reduced the time for messages to travel between the Atlantic and Pacific coasts to about ten days.[1] From April 3, 1860 to October 1861, it became the West's most direct means of east–west communication before the telegraph was established and was vital for tying the new state of California with the rest of the country.
The Pony Express was a mail delivery system of the Leavenworth and Pike's Peak Express Company of 1849 which in 1850 became the Central Overland California and Pikes Peak Express Company. This firm was founded by William H. Russell, Alexander Majors, and William B. Waddell all of whom were notable in the freighting business.
http://en.wikipedia.org/wiki/Pony_Express