Wanda (1970) is not, as is sometimes claimed, the first feature-length film written, directed and acted in by a woman (Ida Lupino directed, co-wrote, and acted in O Mundo é Culpado (1950) in 1950). Though it's difficult to verify, it is possible, however, that Wanda (1970) may be the first American feature-length film to be solely written and directed by a woman who acted in the film's starring role.
Barbara Loden got the idea for the movie after reading a newspaper article about a woman who thanked a judge for sentencing her to 20 years in prison for her participation in a bank robbery, as the woman said she had no sense of direction in her life and believed prison would give her stability. The woman's words resonated with Loden, who felt that she had lived much of her own life without a sense of stability, and who based the character of Wanda on herself at a younger age. Loden also drew inspiration from a book she read about the lives of prostitutes, one of whom recalled enjoying being bossed around by an abusive foster mother because it was the first time in her life someone had told her what to do.
The bulk of the cast was made up of local people who had never acted in a film before.