[12] During World War II, Peck was a conscientious objector and an anti-war activist, and consequently spent three years in jail at Danbury Correctional Institution in Connecticut (1942–1945).
[16] In January 1948, Peck wrote in a letter to the editor in the New York Times, stating that 16 other countries granted amnesty to all WWII COs, and the refusal to do so by the U.S. "seriously belies our professions of democracy.
In April 1948, the WRL assigned Peck to head the Committee on Publicity, which was tasked with printing letters of support for Randolph's call of nonviolent resistance to the draft.
Peck entered the White House in a public tour and quickly chained himself to a banister, and then removed his jacket to reveal a shirt with the hand-painted slogan: "Veto the Draft."
In 1955 and 1956, he was arrested for refusing to take cover during the simulated air raid drills in New York City, which were brought to an end in the early 1960s due to massive civil disobedience.
On June 15, 1955, Peck was one of 28 people arrested for standing in New York City Hall Park during the first major protest against the nationwide air raid drills.
In May 1960, Peck refused to take shelter during the New York City air raid drill along with 500 other persons, marking the largest act of civil disobedience against the program.
Peck was not part of the initial crew, but participated in a week-long fast inside an AEC building, with roughly a dozen other persons in support of the "Golden Rule".
[21] Peck endorsed Martin Luther King Jr.'s Montgomery Campaign, while debating Roy Wilkins of the NAACP about how direct action was just as critically needed as legal procedures in winning civil rights.
During the southern sit-in movement in 1960, Peck and other CORE members performed weekly pickets outside Woolworth stores for 15 months straight in New York City.
Howard K. Smith, reporting on-the-scene for CBS, described the ensuing violence on the radio, in words cited by John Lewis in his 1998 autobiography, Walking with the Wind: "Toughs grabbed the passengers into alleys and corridors, pounding them with pipes, with key rings, and with fists.
On August 2, 1963, Peck was one of 30 people arrested for performing a sit-down in the street, while protesting the discriminatory state policies for the construction of the Downstate Medical Center in Brooklyn.
More than 300 demonstrators were arrested on the Fair's opening day, including CORE leader James Farmer, Bayard Rustin, Michael Harrington and Peck.
On March 19, 1970, Peck was one of 182 demonstrators arrested for obstructing government operations at Manhattan's Armed Forces Examining & Entrance Station, during nationwide, decentralized protests against the war.
On June 10, Peck was arrested in New Jersey with 36 other demonstrators for being involved in the "People's Blockade" campaign, that was conducted at navy ship yards to prevent ammunition from being sent to Vietnam.
On October 1, 1974, Peck was one of a dozen people arrested at the UN for setting up a tiger cage replica, protesting the mistreatment of Vietnamese political prisoners by U.S.-backed forces.
On March 1, 1975, Peck was one of 62 demonstrators arrested for engaging in sit-downs during a tour of the White House in protest against President Ford's conservative amnesty plan.
In the summer of 1977, Peck and American poet Millen Brand traveled to Japan and joined the march from Nagasaki to Hiroshima, the most famous feeder route of the thirteen involved in the Japanese Peace Walk.
When Peck returned home from the Japanese Walk, he shared his experiences in a tour through the U.S., sponsored by the WRL and the Mobilization for Survival, one of the largest coalitions of antinuclear groups.
During the Special Session on Disarmament at the United Nations in New York City in the spring of 1978, Peck joined in the major actions launched by the Mobilization for Survival.
That day, Peck was one of 1,045 demonstrators arrested, along with David Dellinger and Daniel Ellsberg, for attempting to block the entrances of the stock market exchange building.
On April 28, 1980, Peck marched with 1,200 demonstrators to the Pentagon, where he and nearly 600 others were arrested for blocking the entrances of the building, including Daniel Ellsberg, Dr. Benjamin Spock, David McReynolds and Grace Paley.
On October 24, Peck joined a thousand people, 1971, protesting an award dinner for Governor Rockefeller, who was responsible for the decision to move in on Attica prison.
Peck criticized the young people at the rally who later broke the windows at Chase Manhattan Bank, which became a big part of the story the following day in the New York Post.
On April 5, 1979, Peck joined a night vigil against the scheduled Alabama execution of John Louis Evans, which ended in celebration when the judge granted a last minute reprieve.
[42] Peck joined 200 people in protesting the United Steelworkers convention in Atlantic City, NJ, on September 23, 1974, over the union's "experimental negotiating agreement" with U.S. Steel Corporation, which prohibited any type of strike.
Peck met Caesar Chavez and spoke with him at length in May 1970, during a mass march from Baltimore to D.C. to protest The Pentagon's purchases of scab grapes to export to troops in Vietnam.
When the conference ended Peck was one of 65 persons to join a motorcade to Fresno, in order to challenge the anti-mass picketing injunction against the UFW, which resulted in more than 400 arrests a week earlier.
The insurance company owned a significant number of citrus fruit groves along the west coast and had stalled previous negotiations for a union contract.
In 1975, Gary Thomas Rowe Jr. testified that he was a paid FBI informant in the Klan, and that on May 14, 1961, the KKK had been given 15 to 20 minutes to attack Freedom Riders without interference by the police.