Twenty years ago today President George H.W. Bush signed the Americans with Disabilities Act into law.

The law made it illegal to discriminate on basis of disability, and it required buildings and transportation systems to meet certain accessibility standards.

Lawmakers celebrating the anniversary say the ADA has broken down barriers, created opportunities and transformed lives. 

Rep. Jim Langevin, D-R.I., the first quadriplegic to serve in Congress, said his life is one of those.

"My gosh, how the world has changed for all of us with disabilities," Langevin said noting the changes that have resulted. "So many barriers have been brought down, so many doors have been opened, so many opportunities created. And I went on to run for elective office."

"And I'm so honored to be able to serve in the United States Congress with all of these fine folks who are with us today," he added.

President Obama is hosting an event at the White House Monday night to commemorate the anniversary.