The USS San Francisco was a New Orleans-class cruiser.  She was launched in March of 1933. She was classified as a Heavy Cruiser because of her 8" guns. From the time she was launched until WW2 she made regular patrols.

When WW2 started the San Francisco was reassigned to Pearl Harbor to be refitted with new armaments. On December 7^th of 1941 the San Francisco was in Pearl Harbor awaiting docking and the cleaning of her heavily fouled bottom. Her engineering plant was largely broken down for overhaul. Ammunition for her 5-in and 8-in guns had been placed in storage. Her 3-in guns had been removed to permit installation of four 1.1-in quadruple mounts. And many of her officers and crew were absent. That morning the Japanese began their surprise attack on Pearl Harbor. Luckily the San Francisco was unharmed and after the attack work resumed to make her war ready. Just 7 days later she left the port ready for duty.

Her first action in the Pacific Theater was joining raids against the Japanese installations on the Gilbert and Marshall Islands, in January of 1942. She participated in the battle of Cape Esperance that October, and came out unharmed. Soon afterward the United States officially entered World War II. In November, she participated in another naval battle, this one much deadlier than the last. The Battle of Guadal Canal began as a Japanese Naval force was discovered 27,000 yards from the fleet. The San Francisco took heavy damage when a torpedo bomber kamikazed into her after missing the San Francisco with its torpedo. The San Francisco stayed in the fight, though found herself firing on a friendly target accidentally, the Atlanta. This information was discovered too late and the Atlanta was destroyed. The Japanese ship Nagara began firing on the San Francisco knocking out steering and communication. After recovering steering, the enemy soon ceased fire. And the San Francisco was able to withdraw.

She underwent repairs and modernization thereafter and was relaunched in February of 1943. Over the course of the next year she participated in coastal barrages and invasion preparation for the islands taken by the Japanese. In 1945 she participated in the Battle of Iwo Jima. She participated in other supporting roles such as mine sweeping and coastal support around Okinawa. On July first she was ordered toward the Philippines to begin preparation for Operation Downfall.

On August 6^th and 9^th Japanese cities of Hiroshima and Nagasaki were leveled by US atomic bombs to hopefully avoid the mass of casualties that a land invasion would incur in Operation Downfall. Major General John E. Hull looked into the tactical use of more nuclear weapons for the invasion of the Japanese home islands, even after the dropping of two strategic atomic bombs on Japan (Marshall did not think that the Japanese would capitulate immediately.) Colonel Lyle E. Seeman reported that at least seven Fat Man type plutonium implosion bombs would be available by X-Day, which could be dropped on defending forces. These were not needed though as the eventual surrender by the Japanese prevented Operation Downfall from ever happening.