DON GONYEA, host:

For many disabled Americans, today is an important anniversary. Twenty years ago today, the Americans with Disabilities Act took effect. Some say there's still progress to be made in fully implementing the law, but commentator Ben Mattlin says it literally transformed his life.

Mr. BEN MATTLIN (Writer and Commentator): When I was younger, it was legal to discriminate against people like me. I was born with spinal muscular atrophy. I've always used a wheelchair, and my hands are too weak to scratch an itch. My parents said I could be anything I wanted when I grew up. It wasn't quite true.

Back in the 1960s and '70s, my parents struggled to find a decent school willing to take a handicapped kid. I assumed the problem was I wasn't smart enough. In 1980, I entered Harvard. It was the year Harvard had to become accessible, under a forerunner of the ADA, the Rehab Act of 1973.

The ancient cobblestone campus proved challenging. But what really bothered me was the administration's refusal to grant me roommates. I might impair their experience, one dean explained. Never mind how this segregation would impact mine.

The sting of discrimination worsened after graduation. No one would hire me. Once, an editor invited me to interview for a staff opening, but upon seeing me, she asked, how would you make photocopies? I mean, you'd be here to help us, not for us to help you.

Then, on July 26, 1990, when I was 27, the ADA became law. It didn't get me a job. But it addressed the differences between essential and nonessential job tasks. It identified a reasonable accommodation from an undue hardship a critical distinction for employers and public places alike. If I encountered a restaurant or store with a 6-inch threshold and no ramp, I had constructive language to use, beyond cursing or crying. Most of all, by recognizing the injustices millions of us were confronting, it provided not just legal recourse, but validation and hope.

Now, the ADA's impact is everywhere: Wheelchair lifts on city buses, signs in Braille, sign-language interpreters. Many young disabled people are growing up with a marvelous sense of belonging, entitlement and pride I never had.

Yes, there is still a long way to go. Yet, in redefining the terms of disability, the ADA made us impossible to ignore. So now people should understand we're just part of the human landscape, and we're here to stay.

GONYEA: Commentator Ben Mattlin lives in Los Angeles, where he's working on a memoir. You can comment on his essay at npr.org's Opinion Page. Transcript provided by NPR, Copyright NPR.