Links to video evidence:

BBC Bitesize: how the US got involved.

BBC People's Century: Background to the Vietnam War.

BBC People's Century: US tactics fail.

BBC News: US troops on patrol.

BBC Panorama: US recruits arrive.

BBC People's Century: Contrasting tactics.

BBC People's Century: Tet Offensive and its impact.

20th century Battlefields: Tet Offensive a turning point.

BBC People's War: Protests against the Vietnam War.

Protests for and against the war.

1960s hippies.