A look back through the decades shows what went right in the early years of affirmative action in college admissions, but also what can go wrong even with the best of intentions.

Those who were able, through luck or experience or hard work, to adapt to the culture of institutions that had long been pillars of the white establishment succeeded by most conventional measures. Others could not break through because of personal trauma, family troubles, financial issues, culture shock — the kind of problems felt by many white students as well, but compounded by being in such a tiny minority. And universities at the time, they said, did not have the will or the knowledge to help.

“I think it’s a fair question to ask: Did we really understand or know what we were doing, or could we have predicted what the issues would be?” said Robert L. Kirkpatrick Jr., who at the time was dean of admissions at Wesleyan University in Middletown, Conn., which was part of these early efforts. “The answer is no. I think we were instinctively trying to do the right thing.”

Columbia — an Ivy League campus right next to Harlem — was a particularly revelatory setting. Perhaps nowhere else were the divisions more striking between the privilege inside university gates and the troubles and demands of black people outside them.

The New York Times tracked down many of the nearly 50 black students in Columbia’s Class of 1973, who arrived on campus as freshmen in 1969. Some of them have remained close friends and helped locate others from directories and photographs.