Guy Irving Burch was hired by Margaret Sanger to work for her National Committee for Federal Legislation for Birth Control (NCFLBC) in the 1930s while he was also running the eugenic Population Reference Bureau in Washington, DC. Burch was a eugenicist and racist anti-immigration activist.
His interest in birth control was purely eugenic: on NCFLBC letterhead, he wrote that he had worked to prevent sound American stock from “being replaced by alien or negro stock, whether it be by immigration or by overly high birth rates among others in this country.”
Quoted in Ellen Chesler, Woman of Valor: Margaret Sanger and the Birth Control Movement in America (New York: Simon & Schuster, 1992), 343