Advocate of 'San Babies" Arrifes on England -- Mrs. Margaret Sanger Slee, bearding the Airport bus at Heathrow, London, on her arrival by air from the U.S.A. Mrs. Margaret Sanger Slee, international advocate of planned parenthood, has just arrived at Peathrow Airport, London the U.S.A. by plane. Mrs. Slee says than parents should in bring babies into the world, unless they were sure that the would be well fed. Mrs. Margaret Sanger Slee is a attend a Family Planning Conference at Oxford, England, this month. July 01, 1947. (Photo by Fox Photos).