State nicknames or slogans often reflect the local pride which is associated with each state, and California is no exception. California, even before the Gold Rush, had been associated with gold, and is known as the "Golden State." Reasons for this included the Spanish El Dorado, “the Golden One,” and the name for the entrance of San Francisco Bay, the Golden Gate. One of the earliest published uses of “Golden State” can be found in the title of a book published in 1856 by Eliza Farnham promoting California’s many attractions. The name has only grown in popularity, recalling not just the Gold Rush, but the seemingly limitless possibilities of California. The California Maritime Academy named its first training ship the Golden State. Golden State became the official State Nickname in 1968.

Source: State of California Capitol Museum