Final answer:
The Students for a Democratic Society (SDS) conducted the first protests against the Vietnam War.
Step-by-step explanation:
The Vietnam War sparked a significant antiwar movement in the United States, and the first protests against the war were led by a group called the Students for a Democratic Society (SDS). The SDS was a student organization formed in the early 1960s, and it gained national attention when students at the University of California in Berkeley launched the Free Speech Movement in 1964.