<P> US troop numbers peaked in 1968 with President Johnson approving an increased maximum number of US troops in Vietnam at 549,500 . The year was the most expensive in the Vietnam war with the American spending US $77.4 billion ( US $ 544 billion in 2018 ) on the war . The year also became the deadliest of the Vietnam War for America and its allies with 27,915 South Vietnamese ( ARVN ) soldiers killed and the Americans suffering 16,592 killed compared to around two hundred thousand of the communist forces killed . The deadliest week of the Vietnam War for the USA was during the Tet Offensive specifically February 11 -- 17 , 1968 , during which period 543 Americans were killed in action , and 2547 were wounded . </P>
<P> US troop numbers peaked in 1968 with President Johnson approving an increased maximum number of US troops in Vietnam at 549,500 . The year was the most expensive in the Vietnam war with the American spending US $77.4 billion ( US $ 544 billion in 2018 ) on the war . The year also became the deadliest of the Vietnam War for America and its allies with 27,915 South Vietnamese ( ARVN ) soldiers killed and the Americans suffering 16,592 killed compared to around two hundred thousand of the communist forces killed . The deadliest week of the Vietnam War for the USA was during the Tet Offensive specifically February 11 -- 17 , 1968 , during which period 543 Americans were killed in action , and 2547 were wounded . </P>
what was the highest number of u.s. soldiers in south vietnam at one time
what was the highest number of u.s. soldiers in south vietnam at one time
549,500
549,500