Architectural Barriers Act (ABA) of 1968

The ABA isĀ  and was the first step by Congress to ensure access to the built environment for people with disabilities. The law requires that buildings or facilities that were designed, built, or altered with federal dollars or leased by federal agencies after August 12, 1968 be accessible. Facilities that predate the law generally are not covered, but alterations or leases undertaken after the law took effect can trigger coverage.

Today the The Americans with Disabilities Act of 1990 and Revised ADA Regulations Implementing Title II is a much refined product.

https://www.ada.gov/2010_regs.htm

The law covers a wide range of facilities, including U.S. post offices, Veterans Affairs medical facilities, national parks, Social Security Administration offices, federal office buildings, U.S. courthouses, and federal prisons. It also applies to non-government facilities that have received federal funding, such as certain schools, public housing, and mass transit systems.

The ABA is enforced through standards for accessible design. Four Federal agencies are responsible for these standards: the Department of Defense, the Department of Housing and Urban Development, the General Services Administration, and the U.S. Postal Service. The standards indicate where access is required and provide detailed specifications for ramps, parking, doors, elevators, restrooms, assistive listening systems, fire alarms, signs, and other accessible building elements. Facilities covered by the ABA must meet these standards.