Accessible design is a design process in which the needs of people with disabilities are specifically considered.
Accessibility as a design concern has a long history, but public awareness about accessibility increased with the passage of legislation such as the Americans with Disabilities Act (ADA), which mandated that public facilities and services be fully accessible to people with disabilities.
In 1998 an amendment to Section 508 of the Rehabilitation Act of 1973 was passed. The amendment mandated that the Access Board develop accessibility standards for software, hardware, websites, videos, and other information technology.
Although these standards apply directly to the development, procurement, modification, and use of information technology of U.S. federal agencies, many states, educational institutions, and other entities have adopted them as one way to meet their ADA obligations.
Learn about the difference between accessible, usable, and universal design (Washington.edu article).