After France was defeated in WWII by Germany, the Japanese took control of the main resources of Vietnam - they ruled the area brutally and treated the people cruelly. After WWIII, Vietnam was returned to the French and the Viet Minh entered the city of Hanoi in 1945 and declared Vietnamese independence, leading to a war between the French and the Viet Minh.
In 1946, war broke out between the French and the Viet Minh - war dragged on until 1954 - by the early 50s, the French controlled most cities and the Viet Minh controlled most of the countryside.
China was supported by China, which became Communist in 1949 - now the American saw the Viet Minh as puppets of Mao and the Chinese Communists.
At the Geneva Peace Conference in 1954, Vietnam was decided along the 17th parallel, the North would be under control of the Communist Ho Chi Minh, the South would be under control by the anti-Communist Catholic politician Ngo Dinh Diem - there would be general elections in 1956 for Vietnam to decide its future.
The decisive event was in 1954 at the Battle of Dien Bien Phu - controlled the main routes between Vietnam, Laos and Cambodia. Led to a French defeat and a Viet Minh victory.
The Americans helped Diem to set up the Republic of South Vietnam - they supported him because he was bitterly anti-Communist, set $1.6 billion in aid from 1954 to 1960 and backed Diem's refusal to hold elections in 1956.
Actions of Diem's government increased support for Communist-led National Liberation Front - it was set up in December 1960 and aimed to reunite North and South while introducing economic and social reform.
When Johnson was elected in 1964, he promised to create a 'Great Society' with good living standards, healthcare and other benefits - however Vietnam undermined these plans and became linked to issues of poverty and welfare.
In 1964, the Gulf of Tonkin incident occurred - it was a fabricated event where North Vietnamese patrol boats attacked a US destroyer and was used as an excuse by new President Johnson to take action against North Vietnam. The US Congress passed Tonkin Gulf Resolution gave Johnson the power to 'take all necessary measures to prevent further aggression and achieve peace and security.'
In March 1965, 3,500 US troops came ashore at Da Nang - ended policy of supplying forces.
US forces killed 2000 Viet Cong for the loss of 300 troops.
Johnson announced he was not standing for re-election - was an admission of failure.
In 1968, the Vietcong launched a surprise offensive during the Tet (New Year) festival. They attacked 36 cities and even reached Saigon where they held the US embassy. They were eventually forced to retreat with very heavy losses. From now on, it was the North Vietnamese army that did most of the fighting, rather than the Vietcong.
This was a military victory for the USA but, in the long term, it had a disastrous effect on the attitudes of Americans, especially witnessing their own embassy under attack, as well as the thousands of civilian casualties and thousands of refugees. Opinion was also turning against American involvement in Vietnam.
In March 1968, a unit of American soldiers carried out a search-and-destroy mission on the village of My Lai, killing between 300 and 400 civilians - one of the worst cases of inhumane US behaviour.
After the Tet Offensive, Johnson concluded that the war could not be won militarily - he reduced the bombing campaign and instigated peace talks in Paris in May 1968.
The advancements made by the Viet Cong in the Tet Offensive shocked the American public so much that Nixon decided to introduce the policy of 'Vietnamisation' - training the South Vietnamese army to fight on its own using US arms and then withdrawing US troops.
In November 1969, after the revelations of My Lai, 700,000 anti-war protesters demonstrated in DC - it was the largest political protest in US history.
US troops entered Cambodia in 1970 in order to destroy the Ho Chi Minh Trail - led to worldwide outrage and the Kent State University protests.
At Kent State University in Ohio, students organised a demonstration against Nixon's decision to invade Cambodia - 4 students were killed and 11 injured.
Bombing of Laos began in 1971 - more cluster bombs were dropped on Laos during the war than any other country - ever since the early 1970s, unexploded bombs in Laos have killed more than 12,000 people.
In 1971/2, there were renewed bombing attacks on North Vietnam - caused great destruction to transport, slowing down the progress of invasion from the North.
In 1971 a committee led by William Fulbright investigated the Vietnam War hoping to giving advice on how to end US involvement there.
As people gave evidence, more emerged about the inhumane behaviour of US troops in Vietnam. My Lai was not just an isolated incident. Such behaviour had been encouraged by the military leadership. The effect of these hearings was to raise questions at an official Government level about the purpose of US involvement in Vietnam.
Lieutenant Calley was found guilty of 22 murders and sentenced to 20 years' hard labour - released in 1974.
Kissinger worked out a peace agreement with the North Vietnamese - however Thieu (S. Viet leader) refused to sign it as he thought Americans would abandon him - led to N. Vietnamese pulling out.
Le Duc Tho, Nixon and Thieu signed a peace agreement - main clauses was that all US forces had to leave Vietnam and elections to be held in the future would decide if Vietnam became united or not. Nixon was jubilant, describing it as 'peace with honour.'
In April 1975, Saigon fell to the Communists - remaining US officials were airlifted by helicopter from the roof of the US Embassy whilst civilians either had to flee or surrender to the Communists.