Margaret Sanger wrote this book in 1920 at the high water mark of the first wave of feminism. Women in the United States could now vote, own property, acquire higher education, and many other rights won through hard struggle. Sanger saw a woman's right to control her own body (specifically her reproductive system) as the next big goal. It took more than forty years before a new wave of feminism, along with advances in medical technology, made this attainable.