eugenics movement to sterilize people "unfit" to reproduce. The goal was to improve society by eliminating the reproduction of people with limited intelligence and heritable disorders.
She did not consider herself in that category because her blindness and inability to hear were the result of a childhood illness, not a genetic disorder.
I think I read that she later changed her mind and withdrew support for eugenics.
At the time of eugenics popularity in the Progressive movement of the early 1900s, too little was known about what was genetically inherited to even decide which people to sterilize. Race, ethnicity and poverty were regarded as traits to eliminate through sterilization.
Clinics on Native American reservations began routinely sterilizing Native women regardless of what they came in to be treated for, but especially if they sought gynecological care. They were not informed or asked for consent. They were told bogus diagnoses that could be "cured" with surgery. The same treatment was used on people of Asian and African descent. Children placed in homes due to parental poverty or neglect were sterilized when they reached puberty. Immigrants who could not speak English and came from peasant backgrounds were deemed too intellectually inferior to reproduce.
It's been a while since I read about Helen Keller's involvement in and later detachment from eugenics promotion. I think it was when she learned how the eugenics idea was being applied that she changed her mind. Not sure.
EDIT TO ADD:
https://helenjournal.org/march-2024/once-again