Daniel Callaghan was born on July 26, 1892, in San Francisco, California. He graduated from the U.S. Naval Academy in June 1911, and served aboard the armored cruiser USS California (ACR-6) before being commissioned an Ensign in March 1912. Callaghan transferred to the destroyer USS Truxton (DD-14) in March 1915 and to the cruiser USS New Orleans (CL-22) in November 1916. He served with the Bureau of Navigation in Washington, D.C., during World War I, and then served on the battleship USS Idaho (BB-24) before serving with the Board of Inspection and Survey in San Francisco from June 1923 to May 1925. He was then assigned to the battleship USS Colorado (BB-45), followed by a tour on the battleship USS Mississippi (BB-41). Callaghan then returned to the Board of Inspection and Survey until June 1930, when he became Aide to the Commander of Battleships Battle Force and then to Commander in Chief of the U.S. Fleet. He then served as Executive Officer of the Navy ROTC unit at the University of California, Berkley, followed by a tour on the heavy cruiser USS Portland (CA-33). CDR Callaghan then served as Operations Officer to the Commander of Cruisers Scouting Force until July 1938, when he became Naval Aide to President Franklin D. Roosevelt. Capt Callaghan served in this position until May 1941, when he took command of the heavy cruiser USS San Francisco (CA-38). He was promoted to Rear Admiral in April 1942 and became Chief of Staff to the Commander of the South Pacific Force. ADM Callaghan served as Commander of Task Force Sixty-Seven during the Guadalcanal Campaign and he was killed in action on November 13, 1942.
His Medal of Honor Citation reads:
For extraordinary heroism and conspicuous intrepidity above and beyond the call of duty during action against enemy Japanese forces off Savo Island on the night of 12-13 November 1942. Although out-balanced in strength and numbers by a desperate and determined enemy, Rear Admiral Callaghan, with ingenious tactical skill and superb coordination of the units under his command, led his forces into battle against tremendous odds, thereby contributing decisively to the rout of a powerful invasion fleet, and to the consequent frustration of a formidable Japanese offensive. While faithfully directing close-range operations in the face of furious bombardment by superior enemy fire power, he was killed on the bridge of his flagship. His courageous initiative, inspiring leadership, and judicious foresight in a crisis of grave responsibility were in keeping with the finest traditions of the U.S. Naval Service. He gallantly gave his life in the defense of his country.