Students for a Democratic Society (SDS) was the largest of the many organizations that opposed the Vietnam War (1954–75) from the mid-1960s to the mid-1970s. It also gave birth to the most radical and destructive of the antiwar organizations, the Weathermen.

The SDS began in the 1950s as the Student League for Industrial Democracy. The name change came in 1960, but SDS membership held little attraction for most U.S. college students until the publication of "The Port Huron Statement" in 1962. This lengthy expression of the organization's philosophy was written by Tom Hayden (1939–), who would become SDS's next president and later a major figure in the antiwar movement. The "Statement's" critique of American consumerism and racism, and its call for true participatory democracy, appealed to many students' sense of idealism. The SDS chapters began to multiply and membership rosters quickly...