Helen Keller helped found the ACLU, was good friends with Charlie Chaplin and Mark Twain (who were also radical leftists), openly supported and made frequent donations to NAACP, and she was also member of the Socialist Party as well as the Industrial Workers of the World (whose main goal was overthrowing capitalism and aligned itself with anarchism). Most of her speeches were on on topics like disability rights, women's rights, and labor rights.
@Saint_Dionysus she wrote a memoir called out of the dark which I would very much like to read