radical American student organization founded in 1960 to promote participation in government affairs (after the start of the Vietnam War, the group changed its focus to actively protesting the War)
Activist student organization in the U.S. Founded at the University of Michigan in 1960, its chapters were initially principally involved in the civil rights movement. Its "Port Huron Statement" of principles (1962) called for a new "participatory democracy." After organizing a national march in 1965 to protest U.S. involvement in the Vietnam War, it became more militant, organizing student sit-ins to protest universities' participation in defense-related research. By 1969 the SDS had split into factions; the most notorious was the terrorist-oriented Weathermen, or Weather Underground. By the mid-1970s the group was defunct