On the final day of the Madison conference , April 4 , 1971 , hundreds of riot police broke up a block party organized by local Yippies to cap the event , resulting in a street clash between Yippies and police . During an anti-war protest in Washington , D.C. , on November 15 , 1969 , East Coast Yippies led thousands of youths in the storming of the Justice Department building . On August 6 , 1970 , L.A. Yippies invaded Disneyland , hoisting the New Nation flag at City Hall and taking over Tom Sawyer 's Island . While riot police confronted the Yippies , the theme park was closed early for only the second time in the park 's history ( the first being shortly after the assassination of President Kennedy . ) . As many as 23 of the 200 Yippies attending were arrested . Vancouver Yippies invaded the U.S. border town of Blaine , Washington , on May 9 , 1970 , to protest Richard Nixon 's invasion of Cambodia and the shooting of students at Kent State . Columbus Yippies were charged with inciting the rioting that occurred in the city on May 11 , 1972 , in response to Nixon 's mining of North Vietnam 's Haiphong harbor . They were acquitted
assassination of President Kennedy
Assassination of John F. Kennedy
Youth International Party