George Dewey was Admiral of the Navy, the only person in United States history to have attained that rank. He is best known for his victory at the Battle of Manila Bay during the Spanish–American War, with the loss of only a single crewman on the American side.
In the United States Navy, officers have various ranks. Equivalency between services is by pay grade. United States Navy commissioned officer ranks have two distinct sets of rank insignia: On dress uniform a series of stripes similar to Commonwealth naval ranks are worn; on service khaki, working uniforms, and special uniform situations, the rank insignia are identical to the equivalent rank in the US Marine Corps.
General of the Armies of the United States, more commonly referred to as General of the Armies, is the highest military rank in the United States Army. The rank has been conferred three times: to John J. Pershing in 1919, as a personal accolade for his command of the American Expeditionary Forces during World War I; to George Washington in 1976, as a posthumous honor during the United States Bicentennial celebrations; and posthumously for Ulysses S. Grant in 2022 to commemorate the 200th birthday of the Army's first four-star general.
Fleet admiral is a five-star flag officer rank in the United States Navy whose rewards uniquely include active duty pay for life. Fleet admiral ranks immediately above admiral and is equivalent to General of the Army and General of the Air Force.
A flag officer is a commissioned officer in a nation's armed forces senior enough to be entitled to fly a flag to mark the position from which the officer exercises command.
General of the Army is a five-star general officer and the second-highest possible rank in the United States Army. It is generally equivalent to the rank of Field Marshal in other countries. In the United States, a General of the Army ranks above generals and is equivalent to a fleet admiral and a general of the Air Force. The General of the Army insignia consisted of five 3⁄8-inch (9.5 mm) stars in a pentagonal pattern, with touching points. The insignia was paired with the gold and enameled United States Coat of Arms on service coat shoulder loops. The silver colored five-star metal insignia alone would be worn for use as a collar insignia of grade and on the garrison cap. Soft shoulder epaulettes with five 7⁄16-inch (11 mm) stars in silver thread and gold-threaded United States Coat of Arms on green cloth were worn with shirts and sweaters.
Admiral is a four-star commissioned officer rank in the United States Navy, the United States Coast Guard, and the United States Public Health Service Commissioned Corps with the pay grade of O-10. Admiral ranks above vice admiral and below fleet admiral in the Navy; the Coast Guard and the Public Health Service do not have an established grade above admiral. Admiral is equivalent to the rank of general in the other uniformed services. The National Oceanic and Atmospheric Administration Commissioned Officer Corps has never had an officer hold the grade of admiral. However, 37 U.S.C. § 201 of the U.S. Code established the grade for the NOAA Corps, in case a position is created that merits the four-star grade.
A five-star rank is the highest military rank in many countries. The rank is that of the most senior operational military commanders, and within NATO's standard rank scale it is designated by the code OF-10. Not all armed forces have such a rank, and in those that do the actual insignia of the five-star ranks may not contain five stars. For example: the insignia for the French OF-10 rank maréchal de France contains seven stars; the insignia for the Portuguese marechal contains four gold stars. The stars used on the rank insignias of various Commonwealth of Nations are sometimes referred to colloquially as pips, but are stars of the orders of the Garter, Thistle or Bath or Eversleigh stars depending on the wearer's original regiment or corps, and are used in combination with other heraldic items, such as batons, crowns, swords or maple leaves.
A tombstone promotion is an advance in rank awarded at retirement. It often does not include any corresponding increase in retired pay, in which case it is an honorary promotion whose only benefit is the right to be addressed by the higher rank and to carve it on one's tombstone.
A general officer is an officer of high military rank; in the uniformed services of the United States, general officers are commissioned officers above the field officer ranks, the highest of which is colonel in the Army, Marine Corps, and Air Force and captain, in the Navy, Coast Guard, Public Health Service Commissioned Corps (PHSCC), and National Oceanic and Atmospheric Administration Commissioned Corps (NOAACC).
Harry Handly Caldwell was America's first submarine captain. He became the first naval submarine commanding officer, of any nation, when he assumed command of USS Holland (SS-1) on October 12, 1900.
In the United States Armed Forces, a six-star rank is a proposed rank immediately superior to a five-star rank, possibly to be worn by the General of the Armies or Admiral of the Navy; however, this correlation was never officially recognized by the military or by Congress.
The United States Public Health Service Commissioned Corps uses the same commissioned officer rank structure as the United States Navy and Coast Guard: from ensign to admiral. While the commissioned corps is authorized to use warrant officer ranks W-1 to W-4 under the U.S. Code of law, it does not currently use these ranks.
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United States Navy 
