The late 1960s became increasingly radical as the activists felt their demands were ignored. Peaceful demonstrations turned violent. When the police arrived to arrest protesters, the crowds often retaliated. Students occupied buildings across college campuses forcing many schools to cancel classes. Roads were blocked and ROTC buildings were burned. In 1968, antiwar demonstrators flocked to the Democratic National Convention in Chicago to prevent the nomination of a prowar candidate. As Americans watched on live television, Chicago turned into a battleground as police clubbed and arrested protesters. The Chicago 7 emerged as a show trial following the convention in which Protest leaders Abbie Hoffman, Tom Hayden, Jerry Rubin, Dave Dellinger, Rennie Davis, John Froines, Lee Weiner and Bobby Seale (Seale's case was later separated from the others) were charged with conspiracy. (This in spite of the fact that LBJ's Attorney General Ramsey Clark had found that it was a police riot and nothing else.) Hoffman, Rubin, Dellinger, Hayden, and Davis were charged with and convicted of crossing state lines with intent to incite a riot. Froines and Weiner were charged with teaching demonstrators how to construct incendiary devices and acquitted of those charges. The seven men were acquitted on the conspiracy charges, while all of the convictions were later reversed on appeal.