Throughout this decade, Poitier, who died Thursday at the age of 94, has cultivated a personality of calm and self-confidence and classic style. He became the first black man to win an Oscar for Best Actor, for his portrayal of an easy-going handyman who befriended a group of nuns in “Lilies of the Field” in 1963; months later, Martin Luther King, Jr. would accept the Nobel Peace Prize, making them twin symbols of black excellence. Always aware of its cultural power, Poitier strove to select roles that would help Hollywood break out of the toxic tradition of African-American actors relegated to roles of servants, musicians, and degrading comic relief. In “The Slender Thread,” he took on the race neutral role of a crisis hotline volunteer. “A Patch of Blue” (1965), in which he plays a man who befriends a blind white girl, and “To Sir, With Love” (1967), in which he plays a teacher in a white school of the working class of London, were both parables of racial healing and mutual understanding.