Born in Lorain, Ohio, King served in the Spanish–American War while still attending the United States Naval Academy. He received his first command in 1914, leading the destroyer in the occupation of Veracruz. During World War I, he served on the staff of Vice Admiral Henry T. Mayo, the commander of the United States Atlantic Fleet. After the war, King served as head of the Naval Postgraduate School, commanded a submarine squadron, and served as Chief of the Bureau of Aeronautics. After a period on the Navy's General Board, King became commander of the Atlantic Fleet in February 1941.