<human>:  What is the history of the Pony Express?
<bot>: The Pony Express was a mail service that operated in the United States of America from April 1860 to November 1861. It was inaugurated to provide rapid communication between the Atlantic and Pacific coasts of the United States, as there were still no transcontinental railroad or telegraph line. Riders of the Pony Express traveled along an extensive network of over-land trails and were often at risk to Indian attacks. The service went through some major changes in its short time, including the addition of mules for the Montana-Utah routes, increased fees for packages, and extending its reach to Salt Lake City. The Pony Express had a total of over 190 stations and employed up to 500 riders. The Pony Express became obsolete with the completion of the First Transcontinental Telegraph in October 1861, which provided a faster and more reliable service.