It was the first comprehensive civil rights law for people with disabilities.
The law made sure they have the same rights and opportunities as all Americans. Including employment, education and transportation.
Karen Tamley, President and CEO of Access Living attended the signing 35 years ago.
Part 1 - Our Chicago: 35 years of the Americans with Disabilities Act
"There were hundreds of disabled people on the White House lawn. And I had no idea, really, at the time how just the stroke of the pen by President H.W. Bush would literally change the lives of millions of disabled people all across the country," Tamley said.
Tamley said life before the ADA was quite different, she said the world was largely inaccessible.
She said buses, bathrooms and other public places were inaccessible. She had to be carried into stores and restaurants.
Attitudes towards people with disabilities were different too.
Sujatha Jagadeesh Branch is the Vice President for Civil Rights and Systemic Litigation at Equip for Equality. She explained there was a lot of ignorance.
"Folks who didn't have disabilities had pretty minimal opportunity to interact with people who do have disabilities," she said. "Before the ADA, there was a lot of ignorance, a lot of pity and shaming, and a lot of discrimination."
Part 2 - Our Chicago: 35 years of the Americans with Disabilities Act
Branch added that now there are more opportunities for people with disabilities to be to live, work and play where they want to.
Tamley said there are many areas where more work is needed.
"I would say one thing that still needs work is the area of employment and economic opportunity. We still have widespread poverty in the disability community. Data shows that disabled people are twice as likely to live in poverty than those without disabilities," Tamley said.