She was launched 28 April 1904 by Union Iron Works, San Francisco, California, sponsored by Miss Florence Pardee (daughter of California governor George C. Pardee), and commissioned 1 August 1907, Captain V. L. Cottman in command.
Joining the 2nd Division, Pacific Fleet, California took part in the Naval Review at San Francisco in May 1908 for the Secretary of the Navy. Aside from a cruise to Hawaii and Samoa in the fall of 1909, the cruiser operated along the west coast, sharpening her readiness through training exercises and drills, until December 1911, when she sailed for Honolulu, and in March 1912 continued westward for duty on the Asiatic Station. After this service representing American power and prestige in the Far East, she returned home in August 1912, and was ordered to Corinto, Nicaragua, then embroiled in internal political disturbance. Here she protected American lives and property, then resumed her operations along the west coast; she cruised off California, and kept a watchful eye on Mexico, at that time also suffering political disturbance.
"On April 9, 1913, a liberty party from the U. S. S. California, including Corrie, went ashore at Guaymas. A number of the men visited saloons and came under the influence of intoxicating liquor. They caused some disorder in the streets, and Cipriano Lucero interfered. He wore no uniform, but his capacity of policeman was known at any rate to some of the seamen. A struggle broke out between Corrie and Cipriano Lucero, the latter trying to take from Corrie a beer bottle which he had in his possession. During the struggle a number of beer bottles were thrown in the direction of the fighters by some of the seamen. At least one of those bottles hit Cipriano Lucero but without doing him any serious harm. Another bottle hit Corrie, who staggered back and was seized by the right arm by a member of the ship's patrol just reaching the scene of the disorder. Cipriano Lucero then drew his revolver and shot Corrie, and as some of the seamen and one Schlenther, belonging to the ship's patrol, attempted to disarm Lucero, the latter fired another shot which instantly killed one Klesow, master-at-arms, United States Navy, who was trying to push back sailors, from the scene of the fighting."
San Diego's essential mission was the escort of convoys through the first dangerous leg of their passages to Europe. Based on Tompkinsville, New York, and Halifax, Nova Scotia , she operated in the weather-torn, submarine-infested North Atlantic safely convoying all of her charges to the ocean escort. On 19 July 1918, bound from Portsmouth, New Hampshire, to New York, while ten miles southeast of Fire Island San Diego suffered an explosion and sank in 28 minutes with the loss of six lives, the only major warship lost by the United States in World War I. Her commanding officer, Harley H. Christy, survived the wreck.
The Navy initially declared that she had been torpedoed by the German submarine U-156. Later historians believe that it was sunk by a mine laid by a U-boat. However, U-156 carried no mines, and the blast hole is remarkably far toward the cruiser's stern - an unlikely place to strike a mine. The exact cause of the sinking remains a mystery to this day.
Other possibilities include a fire caused by spontaneous combustion in the coal bunkers could have ignited ammunition stored nearby, and sabotage by a German agent, a theory raised by the release of secret Russian documents that asserted a spy planted a bomb aboard.
The wreck presently lies in 33 m (110 ft) of water, with the highest parts just 20 m (65 ft) below the surface, and as a result is one of the most popular shipwrecks in the US for scuba diving. Unfortunately the wreck lies inverted (upside-down) and has decayed over the last century. The wreck has claimed the lives of a number of divers over the years but this has not diminished its popularity. Nicknamed the "Lobster Hotel" for the abundance of lobsters living there, it is also a home to many kinds of fish.
The wreck is listed in the National Register of Historic Places.