The Anti-Vietnam War Movement was a period of civil unrest that occurred during the Vietnam War (1955-1975). It was a collective effort by citizens, activists, and organizations to oppose the U.S. involvement in the war and to call for an end to the conflict
From Wikipedia
Opposition to United States involvement in the Vietnam War reached a substantial scale in 1965 with demonstrations against the country's escalating role in the war. Over the next several years, these demonstrations grew into a social movement which was incorporated into the broader counterculture of the 1960s.