The disability rights movement transformed the question of disability from a personal tragedy requiring medical intervention to a social justice issue requiring structural change: the problem is not primarily the impairment but the built environment and attitudinal barriers that disable people who have it. The Americans with Disabilities Act, and its equivalents globally, instantiated this principle in law — imperfectly, and with ongoing battles about scope and enforcement. The movement's watchword — 'Nothing about us without us' — is one of the clearest articulations of the participation principle that justice requires.
Each step builds on the last.