From a New York Times review by Dwight Garner of the book edited by Christian Gregory titled “The Essential Dick Gregory”:

By the time I was old enough to know who Dick Gregory was, in the early 1980s, he was on the downslope of his career. He’d left stand-up comedy, where he’d been a pioneer. His work during the civil rights era — he marched in Selma, and had been close to Medgar Evers and Martin Luther King Jr. — was behind him too.