In 1969, the U.S. Supreme Court unanimously reversed those convictions, saying there was no evidence they were responsible for the violence.
Amid that legal case, Mr. Gregory ran for mayor against Daley in 1967 and for U.S. president in 1968 as a write-in candidate with the left-wing Freedom and Peace Party, campaigning against what he saw as rampant political corruption in the two major parties.
Mr. Gregory said he was appalled that the Democratic Party would host its national convention that year in Chicago, a city where black demonstrators were regularly brutalized by the police. The convention drew a large contingent of white anti-Vietnam protesters, and the outbreak of violence that ensued prompted Mr. Gregory to take mordant glee in the melee.
“I was at home watching it on TV, and I fell on the floor and laughed,” he told GQ magazine in 2008. “My wife said, ‘What’s funny?’ And I said, ‘The whole world is gonna change. White folks are gonna see white folks beating white folks.’ ”
Mr. Gregory took part in highly publicized fasts for peace during the Vietnam War — which resulted in a close friendship with ex-Beatle John Lennon. In 1980, he traveled on his own to Tehran on a mission to free the Americans held in the U.S. Embassy and began a fast that reduced him to 97 pounds, before he was forced by the Iranian revolutionary government to leave.
Increasingly inclined to believe conspiracy theories, he was once arrested for attempting to wrap yellow “crime scene” tape across the front gates of the CIA, for what he alleged was the spy agency’s involvement in distributing crack cocaine in inner cities.
Like Muhammad Ali, “who always thought of himself as more than a boxer, Greg always considered himself more than a comic,” New York Times sports columnist and Gregory biographer Robert Lipsyte told the London Independent in 2004. “Both men suffered enormously for their political convictions. But unlike Ali, Greg was conscious of his role from the beginning. He knew that his presence at Southern demonstrations would save lives, even if it killed his career.”
Richard Claxton Gregory was born in St. Louis on Oct. 12, 1932. He was the second of six children and described his family as perpetually on relief. He said his father, an alcoholic, was largely absent.
He and his siblings often did not have suitable clothes to wear and would don their mother’s dresses to go outside and play. “The kids laughed at us and called us names,” Mr. Gregory told Ebony magazine in 2010. “I ignored the fact that I was wearing a dress and made fun of them, too. My jokes were funnier. Before I knew it, I had an audience every day.”
He developed a sinewy build and became a distinguished runner in high school. He was accepted at Southern Illinois University at Carbondale, where he captained the cross-country and track teams and continued winning championships.
After his sophomore year, he left college and spent two years in the Army, where he entertained G. I.s in talent contests. His prowess at joke telling spurred his desire for a show-business career. He eventually made his way to Chicago, holding down brief jobs at the post office and elsewhere.
In his off-hours, he was a master of ceremonies in black clubs, earning $10 a night. He briefly owned his own club, and he mostly supported himself during these years with his wife’s modest secretarial salary.
He had married Lillian Smith in 1959, and they would have 11 children, one of whom, Richard Jr., died of pneumonia at 10 weeks. A complete list of Mr. Gregory’s survivors was not reported.
Gradually, Mr. Gregory grew a small but devoted fan base and made influential contacts. He caught a break in 1961 when Hugh Hefner requested that the comedian perform one night at Chicago’s Playboy Club to substitute for Irwin Corey, who had canceled at the last minute.
As Mr. Gregory told it, when he arrived at the club that night, he was stopped by the manager. The man feared an especially hostile audience — a convention of white Southern frozen-foods executives.
Mr. Gregory strode onto the stage anyway and grabbed the microphone. A heckler quickly stood up and threw out a racial epithet.
The comic was ready. He calmly explained that he had an arrangement with the club that he received a $50 bonus each time someone used that word and invited the audience to keep on saying it.
Another in the crowd asked Mr. Gregory if he’d consider performing in Mobile, Ala. He replied: “Mobile? I won’t even work the south of this room.”
He won over the audience, and an ensuing profile in Time magazine led to invitations to appear on Paar’s TV show and other career-building stops. As he rose in the national consciousness, he also relished playing the provocateur. He often said he titled his 1964 memoir “Nigger: An Autobiography” — a book co-written with Lipsyte — so that every time the slur was spoken, it would serve as advertising for the book. It quickly became a bestseller.
“Powerful and ugly and beautiful,” journalist Milton Esterow wrote in his Times review, “a moving story of a man who deeply wants a world without malice and hate and is doing something about it.”
By the early 1970s, Mr. Gregory had largely made his comedy career secondary to his broadening activism, although he periodically returned to performing.
Out of civil rights grew his interest in causes such as eliminating world hunger, ending capital punishment and improving health care for blacks. He became a vegetarian, he said, out of his commitment to nonviolence, and that led to an unlikely career as a diet guru.
In the 1980s, he began a venture called Dick Gregory Health Enterprises, a maker of weight-loss and nutritional products that included the “Slim-Safe Bahamian Diet.” He went on the lecture circuit to promote his controversial diet plan, which once brought him a reported $100,000 in monthly royalties.
A falling out with business partners ended that. Then came tax trouble and, by 1990, he said that he owed more than $1.2 million to the Internal Revenue Service and creditors including banks and American Express.
Over the years, he had to sell a farm near Plymouth, Mass., where he had long made his home. Watkins said that Mr. Gregory was supported financially by Cosby during hard times.
In later years, Mr. Gregory’s public statements perpetuated conspiracy theories about the role the U.S. government played in the assassinations of civil rights leaders, the 9/11 attacks, the rise of the Islamic State terrorist group and the spread of the Ebola virus.
He also maintained a busy role as an activist, in 2004 courting arrest by protesting in front of the Sudanese Embassy in Washington to bring attention to genocide in the Darfur region.
He also campaigned, unsuccessfully, to remove J. Edgar Hoover’s name from the FBI headquarters in Washington. He said he had seen Hoover’s FBI memos from the 1960s — released through the Freedom of Information Act — showing the longtime FBI director’s intentions to “neutralize” him.
At the very least, he said, his phone was probably bugged. He quipped, “I tell people, ‘If you want to send a message to the White House, call my house.’ ”
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