According to the website for the Americans with Disabilities Act:
The Americans with Disabilities Act of 1990 (ADA) prohibits discrimination and ensures equal opportunity for persons with disabilities in employment, State and local government services, public accommodations, commercial facilities, and transportation. It also mandates the establishment of TDD/telephone relay services.
The law is designed to protect individuals from discrimination, afford individuals equal access to public facilities and services, and enable society to benefit from the skills and talents of persons with disabilities.
The ADA was revised by the ADA Amendments Act of 2008 (P.L. 110-325), which became effective on January 1, 2009.
For more information, visit Introduction to the ADA.