"Although American scientists had been busy studying hormones in the 1930s and 1940s, Marga-ret Sanger's dream of a pill for birth control improbably came to fruition because of the discovery of a wild Mexican yam. The yam was key to the development of synthetic hormones, a scientific advance necessary for the creation of the Pill."
January 1, 1970
https://en.wikiquote.org/wiki/Hormonal_birth_control