From the Ghirardelli site:

"The Ghirardelli Chocolate Company is an integral part of the fascinating history of the development of chocolate into the most craved flavor of consumers today. The origination of chocolate dates back over 4000 years to the culture of the Mayas in Central and South America, then to its introduction in Europe in the 1500, its re-invention by European chocolatiers as a sweet, creamy confection, and its re-introduction into the New World and America in the 1800's. The Ghirardelli Chocolate Company played an integral role in the introduction of chocolate to American consumers, establishing its enduring chocolate reputation from its San Francisco factory in 1852. Today, it has built on its signature taste, and time-honored manufacturing processes to become America's Premium Chocolate."

Also from the Ghirardelli site:

"The History of Chocolate:

Origin: Amazon or Orinoco basin of South America approximately 4000 years ago

A.D. 600: The Mayas undertook a massive migration which led this highly civilized people from Central America deep into the northern regions of South America. In Yucatan they established the earliest known cocoa plantations. There is no doubt, however, that the Mayas must have been familiar with cocoa several centuries earlier.

1000: From the very early days of cocoa the peoples of Central America used beans as a form of payment. The use of cocoa beans as units of calculation must also have become established before A.D. 1000. One Zontli equalled 400 cocoa beans, while 8000 beans equalled one Xiquipilli. In Mexican picture scripts a basket with 8000 beans represents the figure 8000.

1200: By subjugating the Chimimeken and the Mayas, the Aztecs strengthened their supremacy in Mexico. Records dating from this period include details of deliveries of cocoa which were imposed as tributes on conquered tribes.

1502: First European contact with Cocoa Beans (4th voyage of Christopher Columbus)

1528: Hernando Cortez returns to Spain with Cocoa Beans, impressed by the fact that the Aztecs used them as currency. H seeded plantations on Trinidad, Haiti and the West African island of Bioko to grow "money" to trade with Aztecs for gold. Spain then had a virtual monopoly of the cocoa market for almost a century.

Early 1700s: The industrial revolution mechanizes chocolate making and brings the price within the public's reach. Chocolate houses start to spring up in England to compete with coffeehouses. (Chocolate at this point was consumed as a liquid beverage, not as a confection.)

1765: The first chocolate factory was established in Massachusetts Bay Colony.

1828: Conrad Van Houten, a Dutch chemist, learns to press cocoa butter out of chocolate liquor. This then allows the production of cocoa powder.

1848: Conrad Van Houten adds cocoa butter and sugar to chocolate liquor and "eating chocolate" was created.

1852: Domingo Ghirardelli establishes his first chocolate factory in San Francisco.

1875: Daniel Peter and Henri Nestle combine chocolate and milk powder and create the first Milk Chocolate Bar.

1879: Rodolphe Lindt produces chocolate that melts on the tongue. He develops the "conching" process that gives chocolate a smoother texture.

1900: Ghirardelli Chocolate Company sells its coffee and spice business, limiting its products to chocolate and mustard. A two-story warehouse (now called the Cocoa Building) is built on North Point Street.

1965: San Francisco declares Ghirardelli Square an official city landmark.

1967: Production of Ghirardelli Chocolate moves to San Leandro, CA.

1998: Lindt and Sprungli Chocolate out of Switzerland acquires Ghirardelli chocolate as a wholly owned subsidiary of their holding company.

Today Chocolate is a multi-billion dollar industry and is one of the most popular confection products in the world."