Before long, similar campus clubs were cropping up—in the Boston area and beyond—“simultaneously” and “spontaneously,” says Sharon Tentarelli, who as a high-school junior in 1989 founded the GSA at the prestigious boarding school Phillips Academy Andover.

Read: A friendship forged through the gay-rights movement

GSAs sprang up organically because of the presence of leaders who felt a need for them, not a national leadership structure that swooped in and set them up. Though they varied in size and strategy from group to group, they tended to share the same basic vision, one articulated by Kevin Jennings, now 56, then a young high-school history teacher at a Boston-area boarding school called Concord Academy: Make gay students feel less alone. In 1988 he founded the first club to bear the “GSA” moniker.

Born and raised in the South in a fundamentalist Christian family whose relatives included members of the KKK, Jennings grew up surrounded by racial intolerance and homophobia, he says. At age 16, he attempted suicide. Upon graduating from high school, he immediately moved to New England to attend Harvard. He remained closeted until the same year he founded Concord’s GSA, coming out in front of the entire school at the age of 25. By the time he came out, he was already in his second teaching job; he’d been “forced out” of his first one, Jennings told me, because he was gay. At the second school, he grew close to a student of his who, upon figuring out his teacher was gay, confided that he, too, liked men. The student would visit him in his office and admit he was suicidal. “Why shouldn’t I kill myself?” the student would ask. “My life isn’t worth saving anyways.”

It was a pivotal moment for Jennings, who went on to co-found the LGBTQ-youth advocacy organization today known as GLSEN (formerly the Gay, Lesbian, and Straight Education Network), write various books on LGBTQ justice in schools, and serve as an assistant secretary in the Department of Education under President Barack Obama. “From that moment,” he told me, “I made a little promise to myself that I would do whatever I could to ensure LGBT youth didn’t grow up feeling that way anymore.”