"I'm sure Hillary would have paid a fortune for them: 'Is this who you want picking up the phone at 3 a.m.?'" the photographer told the LA Times. "I could have made a boatload of money, probably, but I wanted to do it right."
But Jack kept the priceless pics under lock and key until after the November election.
Obama attended Occidental College from fall 1979 through spring 1981. The future president then transferred to Columbia University in New York.
Jack told The Times she crossed paths with the future president at a campus snack shop. The meeting led to a photo shoot in the living room of her Eagle Rock apartment, according to the Times.
The photos, including Obama smoking a cigarette while wearing a Panama hat, first appeared in Time magazine's "Person of the Year" issue. The M+B Gallery exhibit includes 21 of Jack's 36 photos.
Jack told the Times she found the negatives in her Minneapolis home early last year. She kept the photos secret until after Obama was elected president.
Jack, now a professional psychologist, put the negatives in a safety deposit box until after the election.
The M+B Gallery exhibit is scheduled to open Thursday.