DENVER — Rennie Davis, one of the “Chicago Seven” activists put on trial for organizing an anti-Vietnam War protest outside the 1968 Democratic Convention, died Tuesday. He was 80.

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Davis’ wife, Kirsten Liegmann, announced his death on his Facebook page. Liegmann said the cause of death was lymphoma, adding that a large tumor was discovered only two weeks ago.

Davis died at his home in Berthoud, Colorado, according to The Associated Press.

After graduating from Oberlin College in Ohio, Davis joined the top ranks of Students for a Democratic Society and the National Mobilization Committee to End the War in Vietnam, The New York Times reported. In 1967 he joined SDS leader Tom Hayden and traveled to an international conference of student radicals in Bratislava, Czechoslovakia. He also traveled to the North Vietnam capital of Hanoi.

In 1968, Davis helped organize a group that descended upon the 1968 Democratic National Convention in Chicago, the Times reported. A rally at Grant Park on Aug. 27 turned into a riot, with police clubbing thousands of demonstrators, the newspaper reported.

Davis was also injured during the riot.

Federal officials charged Davis and seven others with conspiracy and inciting to riot, the Times reported. Originally called the Chicago Eight, the group was renamed the Chicago Seven when Black Panther leader Bobby Seale was tried separately. Seale was convicted but had his verdict overturned on appeal.

In 1970, the seven defendants were acquitted of conspiracy, but Davis and four others -- Abbie Hoffman, Jerry Rubin, David Dellinger and Hayden -- were convicted of inciting a riot and sentenced to five years in prison. Co-defendants John Froines and Lee Weiner were acquitted, the AP reported.

The guilty verdicts were overturned on appeal.

Davis was “one of the most important nuts and bolts organizers of the anti-war movement in the 1960s and the early 1970s” and an “essential organizer,” David Farber, a distinguished professor of history at the University of Kansas, told the AP.

“He was the one negotiating with the (Mayor Richard J.) Daley administration, trying to get permits and the right to march and rally,” Farber told the AP. “He was the hands-on organizer ... doing very practical, pragmatic things.”

Davis was born May 26, 1940, in Lansing, Michigan, and was raised in Berryville, Virginia.

“One of the things people always said about Rennie Davis was that he was a gentle man. He was not a rabble-rouser, he was not an angry, hostile person,” Farber told the AP. “He deeply believed in a more just and fair and equitable society and pursued it nonviolently all his life.”

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