I'm afraid you still don't know much. It's a consummate irony that nearly every reference to Margaret Sanger & Planned Parenthood that appears on Medium is taken directly or indirectly from the Family Research Council. FRC, of course, is one of the country's oldest & best organized anti-choice, anti-abortion orgs. They've portrayed Sanger as a racist eugenicist & Planned Parenthood as a tool to reduce "unwanted" races for decades now.
Finally, progressive writers are, evidently, taking heed.
True, many of Sanger's views were unacceptable. Especially today, when more is known about genetics. And she certainly did address a women's chapter of the KKK, which, she wrote in her autobiography, was "an aroused group," which, to her was a good group to hear her message.
She also founded the first reproductive health services in Harlem, staffed by black physicians & nurses. In 1939 W.E.B. DuBois & Adam Clayton Powell, Jr., were among the advisors in PP's Negro Project, which sought to bring reproductive services & education to poor blacks in the south.
"“I think it is magnificent that we are in onthe ground floor, helping Negroes to control their birth rate, to reduce their high infant and maternal death rate, to maintain better standards of health and living for those already born, and to create better opportunities for those who will be born” she wrote to medical philanthropist Albert Lasker in 1942. Not exactly the sentiment of a KKK fellow traveler.
When she died in '66, Martin Luther King, Jr. wrote: "There is a striking similarity between our movement & Margaret Sanger's early efforts...."
True, Sanger believed that poverty & ignorance were self-perpetuating. Because, actually, they are. Her mission was to ensure that women of all races & creeds obtained control over their own fertility. And yes, her legacy is a mixed, to be sure. Look closely enough & all of our heroes & heroines have tarnish somewhere, somehow.
Form your own opinion re Sanger & PP, just bear in mind that nearly everything you read here comes from an organization that would happily see the return of women as unwilling brood mares.