Americans with disabilities are a significant minority group in the United States, making up a fifth of the overall population and over half of Americans older than eighty. There is a complex history underlying the United States and its relationship with its disabled population, with great progress being made in the last century to improve the livelihood of disabled citizens through legislation providing protections and benefits. Most notably, the Americans with Disabilities Act is a comprehensive anti-discrimination policy that works to protect Americans with disabilities in public settings and the workplace. Definitions According to the Social Security Advisory Board, when the federal government first began provisioning funds for state-run disability assistance programs, eligible beneficiaries were defined as needing to be "totally and permanently disabled". In 1956, this definition was expanded by the Disability Insurance Program to describe disability as the "inability to engage in any substantial gainful activity by reason of any medically determinable physical or mental impairment which can be expected to result in death or to be of long-continued and indefinite duration." Critics indicated that this language limited the concept of disability to an occupational scope, and more holistic definitions were adopted as time passed. The modern consensus on disability within governmental, medical, sociological realms in the United States is that it includes impairments that either physically or mentally incapacitate individuals from engaging in significant life activities, or the perception of possessing such an impairment. For instance, in a 2013 study, the Centers for Disease Control and Prevention (CDC) evaluated disability across five dimensions: vision, cognition, mobility, self-care, and independent living. Specific conditions that fall under this umbrella vary circumstantially, however it is broadly accepted that disability includes, but is not limited to the following: Autism Autoimmune conditions (ex. lupus, fibromyalgia, rheumatoid arthritis, HIV/AIDS) Blindness or poor vision Cancer Cardiovascular or heart disease Celiac disease Cerebral palsy Deaf or hard of hearing Depression or anxiety Diabetes Epilepsy Gastrointestinal disorders (ex. Crohn's Disease, IBS) Intellectual disability Missing limbs or partially missing limbs Nervous system conditions (ex. migraine headaches, MS, Parkinson's disease) Psychiatric conditions (ex. bipolar disorder, major depressive disorder, PTSD, schizophrenia) History At a federal level, legislation pertaining to disability was limited in the 18th and 19th centuries, with notable laws at that time including an act for the relief of sick and disabled seamen, which was signed by John Adams in 1798. In the early 1900s Eugenic Sterilization