1864-S Double Eagle - 1864-S $20 NGC AU55. Type 1 Double Eagle. This Civil War dated, Western branch mint 1864-S Double Eagle smolders with mint luster in protected areas. The strike is strong with full details on the centers of the stars and the design details of the reverse. Just a trace of wear on Libertys hair and the back of the coronet keeps this coin from a Mint State grade. The surfaces are original and clean for the grade with no individual abrasions worthy of mention.

The San Francisco Mint opened in 1854 because of the need to coin gold resulting from the California Gold Rush. In the West there was an abundance of gold bullion, nuggets and dust; however, there was also an acute shortage of circulating coinage. Congress authorized this mint to relieve the shortage and coin silver and gold and because transportation of bullion to Philadelphia was time consuming and hazardous. Because of its proximity to the Gold Rush area, San Francisco was chosen as the site of the new mint.  In 1874 it moved into a new building called the Old United States Mint or the Granite Lady. It is one of the few structures that survived the earthquake of 1906. It remained in service as a mint until 1938, when the present facility opened.

In its first year of operation the Mint made four million dollars in gold coins from bullion. The second building, the Old United States Mint, was designed by Alfred B. Mullett in Greek Revival style. It was built in an E-shape with a central pediment portico. There was a completely enclosed courtyard that had a well. It was these features that saved it in the fire that resulted from the earthquake of 1906. The building was situated on a concrete and granite foundation that was made to prevent tunneling into its vaults. In 1906 there was $300 million, a third of the United States gold reserves, in its vaults. Frank Leach and his men worked heroically to successfully preserve the building and the bullion. The mint was able to resume service and operated until 1937. It was designated a National Historic Landmark in 1961.

Since most of the building was made of sandstone, the nickname of The Granite Lady is a misnomer. Only the basement was made from granite. It was opened to visitors in 1993 and sold to the City of San Francisco for one dollar in 2003 for use as the Museum of the City of San Francisco.

In 1844 Longacre was appointed Mint Engraver through the influence of Senator John C. Calhoun of South Carolina. After overcoming opposition by the Chief Coiner, Franklin Peale, who was fearful that the new Engraver would interfere with his illegal medal manufacturing business using the Mint facilities, Longacre did well. He was responsible for creating many new designs including the Indian Head cent, the two-cent piece, the Shield nickel, the Liberty Head gold dollar, the Indian Princess gold dollar, the three-dollar gold piece, and the Liberty Head double eagle.