Twenty years ago, George H.W. Bush signed into law the Americans with Disabilities Act (ADA), a broad civil rights law that forbids discrimination based on any kind of disability — physical or mental. It gives similar protections against discrimination to Americans with disabilities as the Civil Rights Act of 1964. Some see it as a broad government boondoggle, but it’s the law that makes a simple thing like a curb cut a federal mandate because local governments just didn’t care about the people within their communities who live with a physical or mental disability. Navigating a crosswalk seems like such a simple thing for most of us. But try it in a wheelchair when the curbs don’t have ramps and suddenly it becomes an opportunity to be hit by a car.

More importantly, the law made a significant impact by equating physical and mental disabilities. Up until the mental health parity law was passed in 2008, mental disorders were not always seen as being on the same level as a physical disease, illness or condition. But the ADA made the two equal since Day One, ensuring that people who suffered from severe, chronic depression were treated the same way as someone with a physical disability in the eyes of the law.

The law hasn’t been an unadulterated success. Some analyses suggests employers pass on the costs of complying with the ADA to employees in the form of lower wages. And this article notes that the employment rate of those with disabilities has hardly budged in 20 years — still hovering around 65 percent unemployed.

Twenty years is a long time in which to measure the impact of a law on society. But with something like a disability — whether it is something you can see or something you can’t — perhaps we’re going to need to be a little bit more patient. While a lot of positive changes and education have been achieved with the law, we still have a long way to go so that society as a whole stops viewing people with a disability as “someone else.”

Happy Birthday Americans with Disabilities Act. You’ve made a significant impact so far, and we look forward to another 20 years of improvements and equality for those with any kind of disability.