Washington (CNN) -- President Barack Obama commemorated Monday's 20th anniversary of the Americans with Disabilities Act by signing an executive order to increase government employment of disabled people.
"Not dependence but independence: That's what the ADA was all about," Obama said at a White House reception attended by several hundred guests, including Cabinet members, legislators and activists for the disabled.
The law, which President George H.W. Bush signed July 26, 1990, is credited with smashing barriers and creating opportunities for the disabled in a nation where more than 3 million people 15 and older use wheelchairs.
It prohibits discrimination against disabled people, guaranteeing them equal opportunity in employment, transportation, government services and other areas.
Although some critics say the act can be burdensome, costly and an overextension of the government's authority over the private sector, others say it could be stronger.
Video: ADA: 20 years later
The executive order signed by Obama calls for strategic planning, mandatory training and other steps to increase federal hiring of people with disabilities.
In addition, Obama said, the Department of Justice was publishing rules to prohibit disability-based discrimination by state and local governments as well as private businesses.
He called the 1990 law "one of the most comprehensive civil rights bills in the history of this country" and cited examples of people who faced discrimination for their disabilities or overcame them.
"When told you can't, you responded with that age-old American creed, 'yes, we can,' " Obama said; applause and cheers greeted his 2008 campaign theme.
The outdoor commemoration featured a presentation in sign language by actress Marlee Matlin, who starred in the film "Children of a Lesser God," and musical performances by Nathaniel Anthony Ayers, the subject of the film "The Soloist," and Patti LaBelle.
Also Monday, Democratic Rep. James Langevin of Rhode Island, who is a quadriplegic, became the first person in a wheelchair to preside over the House of Representatives.
Langevin, who was paralyzed as a teenager, credits the community support he received after his injury with inspiring him to go into public service.
