The Presidio mutiny, one of the earliest instances of significant internal military resistance to the Vietnam War, was a sit-down protest carried out by 27 prisoners at the Presidio stockade in San Francisco, California on October 14, 1968. The stiff sentences given out at court martials for the participants (known as the Presidio 27) attracted international attention to the extent of sentiment against the war within the U.S. armed forces and the mutiny became "[p]erhaps the single best known event of the domestic GI movement".