Admiral of the Navy is a rank that has only been held once in U.S. Navy history: by George Dewey. In recognition of his victory at Manila Bay in 1898, Congress authorized a single officer to hold the rank of Admiral, and promoted Dewey to this rank in March 1899. By a Congressional Act of 24 March 1903, Dewey's rank was established as Admiral of the Navy, effective retroactive to March 1899. It was specified that this rank was senior to the four-star rank of Admiral and was equal to Admiral of the Fleet in the British Royal Navy. The rank lapsed with the death of Admiral Dewey on 16 January 1917.
The rank Admiral of the Navy was first seen as a six star rank during the Second World War, with the establishment of the rank of five-star Fleet Admiral. It was during this time that the Department of the Navy specified that the new 1944 version of the rank of Fleet Admiral was to be junior to Dewey's rank of Admiral of the Navy. However, as there has never been an Admiral of the Navy and a Fleet Admiral serving at the same time, the six star rank status has not been totally confirmed.
During the preparations for the invasion of Japan, a proposal was raised by the Navy Department to appoint Chester Nimitz to the rank of Admiral of the Navy and grant him an insignia as a six-star admiral. Proposals for the new six star rank included changing the title to Flag Admiral. The proposal, however, was dropped after the Japanese surrender, and the United States Navy has never officially appointed anyone to the rank of six star admiral. Because of this proposal, Admiral of the Navy is sometimes held to be senior to the rank of Fleet Admiral and the equivalent of the Army's rank of General of the Armies.
Despite his role in the formation of the United States Navy, John Paul Jones has not been named Admiral of the Navy, in comparison to George Washington who was named General of the Armies in 1976 because of his role in the beginning of the United States.