The correct answer to this open question es the following.
Although the question is incomplete and does not provide a list to elaborate on the timeline, we can say that the events that are important to understanding the Vietnam War are the following.
First, we have to understand what happened during the French colonization period in the region of Vietnam, which was known as French Indochina. The problems arose until the degree that the Soviet Union, China, and finally the United States had to intervene in the conflict between the two Vietnams.
During World War II, Vietnamese leader H* Chi Minh created the League for the Independence of Vietnam, and in 1945 he promulgates the independence of North Vietnam, establishing Communism.
That is when the US entered into the conflict because President Harry Truman was decided to stop the Soviet Union and its spread of Communism. The US supported South Vietnam. China and the USSR supported North Vietnam.
In 1954, the Geneva Accords established the border between North and South Vietnam. Ngo Dinh became the leader of South Vietnam. In 1961, President John F. Kennedy sent troops and helicopters to Vietnam.
In 1964, after the Gulf of Tonkin incident, the US Congress authorized more powers for the US President to use the force against North Vietnam.
In 1965, President Johnson send more troops to Vietnam, but in America, people started to question the US involvement in that war. By 1967, young people, students, and citizens if the US took the streets and protest against US participation in the Vietnam War.
In January 1968, the Tet Offensive represents a major set back for the US. Richard Nixon became President of the US in November 1968. President Nixon started what was known as Vietnamization, and order some US troops stationed in Vietnam to return to the US.