<Tr> <Td> 25 </Td> <Td> </Td> <Td> Ridgeway, Matthew! Matthew Ridgway </Td> <Td> U.S. Army </Td> <Td> General </Td> <Td> 11 May 1951 </Td> <Td> Replaced Douglas MacArthur as senior officer during the Korean War, after MacArthur was relieved by Harry S. Truman . Later served as Chief of Staff of the United States Army . </Td> </Tr> <P> Alexander Vandegrift is also frequently included in historical seniority lists due to his status as the first Commandant of the Marine Corps to hold a four - star rank, as is Anna Mae Hays who was the first woman to be promoted to brigadier general in the history of the United States . Historical seniority is rarely referred to after the Korean War since modern military seniority systems had been well - established after the mid 20th century . Expanded seniority lists such as the one listed below do exist mostly in recognition of major military leaders of modern wars and conflicts . </P> <Table> <Tr> <Th> Officer </Th> <Th> Service </Th> <Th> Highest rank </Th> <Th> Date of rank </Th> <Th> Historical significance </Th> </Tr> <Tr> <Td> Westmoreland, William! William Westmoreland </Td> <Td> U.S. Army </Td> <Td> General </Td> <Td> 1 Aug 1965 </Td> <Td> Senior most operational officer of the Vietnam War . Omitted from some historical lists, since Westmoreland served in the later 20th century when the regular military seniority system had already been well established . </Td> </Tr> <Tr> <Td> Rickover,, Hyman! Hyman G. Rickover </Td> <Td> U.S. Navy </Td> <Td> Admiral </Td> <Td> 3 Dec 1973 </Td> <Td> Head of the nuclear program of the United States Navy and one of the longest serving officers in United States military history . </Td> </Tr> <Tr> <Td> Powell, Colin! Colin Powell </Td> <Td> U.S. Army </Td> <Td> General </Td> <Td> 4 Apr 1989 </Td> <Td> Served as Chairman of the Joint Chiefs of Staff during the Gulf War . Later considered for five star promotion; however, a Congressional bill was never passed . Later served as Secretary of State . </Td> </Tr> <Tr> <Td> Schwarzkopf, Norman! Norman Schwarzkopf Jr . </Td> <Td> U.S. Army </Td> <Td> General </Td> <Td> 1 Nov 1988 </Td> <Td> Senior commander of Operation Desert Storm . As with Colin Powell, was considered for five star rank but without result . </Td> </Tr> <Tr> <Td> Petraeus, David! David Petraeus </Td> <Td> U.S. Army </Td> <Td> General </Td> <Td> 30 Jan 2007 </Td> <Td> Considered for five star rank due to his status as the leader of the military during the War on Terror, however due to later scandals after retirement no further effort was made on this proposal . </Td> </Tr> <Tr> <Td> Mattis, James! James Mattis </Td> <Td> U.S. Marine Corps </Td> <Td> General </Td> <Td> 7 Nov 2007 </Td> <Td> Leader of United States Central Command during the Iraq War . Led both the first and second Battles of Fallujah . Secretary of Defense under Donald Trump as of January 20, 2017 . </Td> </Tr> <Tr> <Td> Dunwoody, Ann! Ann E. Dunwoody </Td> <Td> U.S. Army </Td> <Td> General </Td> <Td> 14 Nov 2008 </Td> <Td> First female four star officer in the history of the United States Armed Forces . </Td> </Tr> <Tr> <Td> Wolfenbarger, Janet! Janet C. Wolfenbarger </Td> <Td> U.S. Air Force </Td> <Td> General </Td> <Td> 5 Jun 2012 </Td> <Td> First female four star general in the history of the United States Air Force . </Td> </Tr> <Tr> <Td> Howard, Michelle! Michelle Howard </Td> <Td> U.S. Navy </Td> <Td> Admiral </Td> <Td> 1 Jul 2014 </Td> <Td> First female four star admiral in the history of the United States Navy . </Td> </Tr> </Table> <Tr> <Th> Officer </Th> <Th> Service </Th> <Th> Highest rank </Th> <Th> Date of rank </Th> <Th> Historical significance </Th> </Tr>

What is the highest ranking officer in the army