The trailblazing civil rights activist Judy Heumann died Saturday at the age of 75. Heumann was widely known as “the mother” of the U.S. disability rights movement, for breaking down barriers faced by disabled people and leading campaigns for historic legislation, including the Americans with Disabilities Act.

In 1970, Heumann became the first teacher in New York to use a wheelchair. In 1977, she led a 26-day sit-in protest at a federal building in San Francisco that led to enforcement of the Rehabilitation Act’s prohibition on discrimination against disabled people.

President Biden honored Heumann in a statement, writing, “After her school principal said she couldn’t enter Kindergarten because she was using a wheelchair, Judy dedicated the rest of her life to fighting for the inherent dignity of people with disabilities.”