In a varied career, Gregory briefly attempted political office, running unsuccessfully for mayor of Chicago in 1966 and US president in 1968, when he got 200,000 referendums as the Peace and Freedom party candidate.
In the late 60 s, he befriended John Lennon and was among the voices heard on Lennons anti-war anthem Give Peace a Chance, recorded in the Montreal hotel room where Lennon and Yoko Ono were staging a bed-in for peace.
An admirer of Gandhi and Martin Luther King Jr, Gregory embraced nonviolence and became a vegetarian and marathon runner.
The King Center tweeted that Gregory had elicited us to think and to change. And he made us laugh, too.