With the discovery of gold and silver and the continuous development of the mines in Nevada in the early 1860's giving rise to a rapid increase of trade, there was a need for faster communications both for passengers and mail between the mining towns of Nevada and the California business centers of Sacramento and San Francisco.
To meet this need, Wells, Fargo & Company inaugurated a new Pony Express on August 11, 1862, from San Francisco via Sacramento and Carson City, Nevada, to Virginia City, to carry letters at 10 cents per half-ounce (plus the government stamp). This rose-colored stamp was used during the final months of service.
While the primary purpose of the Transcontinental Pony, as far as letters were concerned, was to transmit news, the Virginia Pony was for speedier service of important business letters and newspapers, as the telegraph was now taking care of the news. This very rare letter was sent with a 25 cent stamp (plus the government stamp. Note the message on the front of the envelope: "Send the furniture, all dark colors."
A pony was used between Virginia City and Placerville, then by rail between Placerville and Sacramento, and by boat between Sacramento and San Francisco. The time between Sacramento and Virgina City was fourteen hours, and from San Francisco twenty-four hours.
All during this time means of transportation was constantly improving. Old roads were widened and new ones constructed. Stages could now travel with greater speed and regularity, so that by the spring of 1865 the Virginia Pony service was no longer a necessity. The last delivery was made on March 17, 1865.
Source: Nathan and Boggs. The Pony Express