Short answers, pulled from the story.
The first visible sign of dissent occurred on the 2nd of May 1964 when fewer than eighty people marched in Harvard Square. This gathering outside Harvard University marked one of the earliest organized protests against American military engagement.
On the 1st of February 1968, General Nguyễn Ngọc Loan executed a Viet Cong officer named Nguyễn Văn Lém in front of journalists in Saigon. A photograph of this execution became an iconic image that shifted public opinion and brought battlefield scenes directly into living rooms across the United States.
By 1965 and 1966, African Americans accounted for twenty-five percent of combat deaths despite representing only a fraction of the total population. This disparity led African American leaders to link civil rights struggles abroad with domestic racial injustice.
Country Joe and the Fish released The Fish Cheer/I-Feel-Like-I'm-Fixin'-to-Die Rag on the 1st of October 1965 which became known as the anthem of the protest movement. Over five thousand Vietnam War-related songs were recorded throughout the decade reflecting increasing anti-war sentiment.
Ohio National Guard troops opened fire on students at Kent State University killing four and wounding nine others on the 4th of May 1970. This tragedy intensified existing tensions between government authorities and dissenters while radicalizing more students across the country.