A six-star rank was a proposed special grade immediately superior to a five-star rank.
On 21 January 1955, the US Senate considered a joint resolution "To authorize the appointment of General of the Army Douglas MacArthur as "General of the Armies of the United States". The resolution stated that this was "in recognition of the great services to his country" he had rendered, and that "the President is hereby authorized to appoint General of the Army Douglas MacArthur to the office of General of the Armies of the United States (which office is hereby revived for this purpose), such appointment to take effect as of the seventy-fifth anniversary of his birth, January 26, 1955." The proposal was shelved and never took effect. Recently, a few authors have described this proposed rank as a six star rank.
George Washington was posthumously promoted to the rank of "General of the Armies of the United States" in 1976. Although the law did not actually specify the number of stars, some U.S. newspapers and Members of Congress describe this as a six-star rank. His appointment had been to serve as "General and Commander in chief of the Army of the united Colonies".
The only officer in the history of the US Military to bear the rank of General of the Armies during his lifetime is General of the Armies John J. Pershing.
General Douglas MacArthur showing five-star rank insignia. A proposal in Congress (1955) that MacArthur be promoted to General of the Armies lapsed
Congressional resolution authorising promotion of Douglas MacArthur to General of the Armies. Copy taken from his service record on file at the National Personnel Records Center
Painting of George Washington showing three star insignia. He was posthumously promoted to the rank of General of the Armies of the United States in 1976
for promoting George Washington to the rank of General of the Armies of the United States effective 4 July 1976