Margaret Sanger started the Birth Control League in 1914 in New York. After WWII, it became the Planned Parenthood federation. Below, I have linked to a newspaper story I posted from 1950. The last line is:
Mrs. Sanger said that the federation should "stress quality as a prime essential in the birth and survival of our population."
That means exactly what it sounds like. She intended birth control and abortion to be used to improve the "quality" of the human race.
http://www.freerepublic.com/focus/news/991823/posts?page=65#65