Ending in a clash with riot police, it set a pattern for the massive protests which followed and due to the size and violence of this event, Johnson attempted no further public speeches in venues outside military bases. Another Mother for Peace group founded. January 14 – 20,000–30,000 people staged a "Human Be-In" in Golden Gate Park in San Francisco, near the Haight-Ashbury neighborhood that had become the center of hippie activity. In February, about 2,500 members of Women Strike for Peace (WSP) marched to the Pentagon. This was a peaceful protest that became rowdier when the demonstrators were denied a meeting with Secretary of Defense Robert McNamara. February 8 – Christian groups opposed to the war staged a nationwide "Fast for Peace." February 23 – The New York Review of Books published "The Responsibility of Intellectuals" by Noam Chomsky as a special supplement. March 12 – A three-page anti-war ad appeared in The New York Times bearing the signatures of 6,766 teachers and professors. The advertisement spanned two and a quarter pages in Section 4, The Week in Review. The advertisement itself cost around $16,500 and was sponsored by the Inter-University Committee for Debate on Foreign Policy. March 17 – a group of antiwar citizens marched to the Pentagon to protest American involvement in Vietnam. March 25 – Martin Luther King Jr., a leader of the civil rights movement, led a march of 5,000 against the war in Chicago. April 4 – Martin Luther King Jr. gave a speech in New York City. "America rejected Ho Chi Minh's revolutionary government seeking self-determination. ... " (See details here.) On April 15, 400,000 people organized by the Spring Mobilization Committee to End the War in Vietnam marched from Central Park to the UN building in New York City to protest the war, where they were addressed by critics of the war such as Benjamin Spock, Martin Luther King Jr., event initiator and director James Bevel, Harry Belafonte, and Jan Barry Crumb, a veteran of the war. On the same date 100,000, including Coretta Scott King, marched in San Francisco. On April 24, Abbie Hoffman led a small group of protesters against both the war and capitalism who interrupted the New York Stock Exchange, causing chaos by throwing fistfuls of both real and fake dollars down from the gallery. May 2 – British philosopher Bertrand Russell presided over the "Russell Tribunal" in