Klein’s magnum opus, Muhammad Ali The Greatest combines his pioneering 1964–65 portrait of the young champion boxer Cassius Clay (released in the states as Float Like a Butterfly, Sting Like a Bee) with his film on the fighter’s classic comeback bout with George Foreman a decade later in Zaire. The only white photographer in the boxer’s camp ("I got as close to Ali as a Jewish New Yorker from Paris could get"), Klein captured the force of Ali’s singular personality as well as the insights of his mentor Malcolm X (filmed by Klein weeks before his assassination) and the bedlam of the boxing world. Over the course of the film, Ali emerges as the Heavyweight Champion of everything American—from media and money making to humor and politics—and, according to Klein, "several things not particularly American, like courage and conviction."