Shortly after the Japanese attack on Pearl Harbor brought the United States into World War II, King was appointed as Commander in Chief of the United States Fleet. In March 1942, King succeeded Harold Stark as Chief of Naval Operations. In December 1944, King became the second admiral to be promoted to fleet admiral. King left active duty in December 1945 and died in 1956.
King was born in Lorain, Ohio, on 23 November 1878, the son of James Clydesdale King and Elizabeth Keam King. He attended the United States Naval Academy from 1897 until 1901, graduating fourth in his class. During his senior year at the academy, he attained the rank of midshipman lieutenant commander, the highest midshipman ranking at that time.