The general who commanded US forces in Vietnam in the early phases of the war has died at the age 91.
Westmoreland refused to accept that the US lost the Vietnam War
William Westmoreland took over as head of the Military Assistance Command in 1964, and oversaw an increase in troop strength to half a million by 1968.
His most notable campaign was his defeat of the communists' Tet Offensive in 1968.
However, the ferocity of the fighting undermined American public support for the war.
As protest movements against the war grew at home, Gen Westmoreland kept pushing for more troops.
Under his command, search and destroy tactics were used, as was the defoliant Agent Orange and the liquid fire, napalm.
But efforts to drive the Viet Cong from the countryside were not particularly successful.
After Vietnam, Gen Westmoreland was highly critical of both the Johnson and Nixon administrations' conduct of the war.
He also accused American television and newspapers of turning people against the war.
"A lesson to be learned," he said, "is that young men should never be sent into battle unless the country is going to support them."
Gen Westmoreland never accepted that the US had lost the Vietnam War, arguing that the US had successfully stopped the rest of Asia falling to communism.
"It's more accurate to say our country did not fulfil its commitment to South Vietnam," he once said.
"By virtue of Vietnam, the US held the line for 10 years and stopped the dominoes from falling."
Gen Westmoreland sued the CBS television network over a documentary film that criticised his command.
After an 18-week trial, the case was settled shortly before it was to go to the jury.
Gen Westmoreland went on to become Army Chief of Staff, a position he held until he retired in 1972.
In 1974, he ran for Governor of South Carolina but failed to win the Republican Party nomination.
He was born in Spartanburg County, South Carolina, on 26 March, 1914.
A graduate of West Point military academy, Gen Westmoreland saw action as a battalion commander during World War II in North Africa and Sicily in 1942.
After the D-Day landings at Normandy in 1944, he was promoted to colonel and soon became chief of staff for the 9th Infantry Division.
He also served in the Korean War with the 187th Airborne Regimental Combat team.
In 1955, after attending Harvard Business School, Gen Westmoreland took a job as secretary to the General Staff in Washington.
He was soon appointed major general - at 41, the youngest man to hold that rank in the army.
After a time as commander of the 101st Airborne Division, he was appointed superintendent of West Point, where he initiated sweeping curriculum changes.
Gen Westmoreland died at a retirement home in Charleston, South Carolina.
He is survived by his wife Katherine, a son and two daughters.