The Vietnam War had significant cultural, social and political impacts. Millions of life were lost, and thousands went missing during the 20-year conflict. Vietnam also became a communist nation as the result of the war.
Technically, the Vietnam War was never a war, at least not for the United States. The United States Constitution mandates that only Congress can declare war. The 2/3 majority required for the declaration to pass was never achieved. Aside from a high number of deaths and a change in the governance of Vietnam, the conflict had a profound cultural and social effect on the United States.
First, it brought war into American living rooms. Television became widespread over the course of the Vietnam conflict, and it became the average American's first glimpse at the realities of war. A counter-culture developed in response to what was being shown on television. People, particularly young people, began to question the authority of the government and refused to accept the status quo passed on to them by their parents and grandparents. They organized to form protests that led to sweeping changes within the American culture.
After the war concluded, the United States was faced not only with the embarrassment of not having stopped the communist takeover of Vietnam, but in having engaged in overly cruel war practices.