Daniel Callaghan was a United States Navy officer who served during World War II. He is best known for his leadership as a Rear Admiral and his role in the Pacific Theater, particularly during the Battle of Guadalcanal. Callaghan commanded the USS San Francisco and played a crucial part in naval engagements against Japanese forces. Tragically, Callaghan lost his life during the naval battle of Guadalcanal on November 13, 1942. His bravery and tactical skills earned him posthumous recognition, including the Navy Cross. Callaghan's contributions to the war effort are remembered as significant in the history of the U.S. Navy.