On cold mornings, Les Goodson shows up early outside the University Club, on a wealthy stretch of Fifth Avenue in Manhattan, and races two panhandlers he has nicknamed Catman and Pimp-the-Baby for a warm spot in front of a steam vent. He launches into “Take Five” on his saxophone, leaving his case open for bills and coins.

In a good week, it’s a living — enough to pay the rent on his railroad flat in Harlem and put food on the table. A few times, he has seen a former classmate, Gregory Peterson, bound into the social club without so much as a nod.

Mr. Goodson, 67, and his classmate were among a record number of black students admitted to Columbia University in 1969. Columbia and other competitive colleges had already begun changing the racial makeup of their campuses as the civil rights movement gained ground, but the assassination of the Rev. Dr. Martin Luther King Jr. in 1968, and the resulting student strikes and urban uprisings, prompted them to redouble their efforts.

They acted partly out of a moral imperative, but also out of fear that the fabric of society was being torn apart by racial conflict. They took chances on promising black students from poor neighborhoods they had long ignored, in addition to black students groomed by boarding schools.