In 1914, Dennett met Margaret Sanger, a birth control advocate. Dennett was intrigued, but did not feel financially secure enough to join the birth control movement at the time. In 1915, Dennett wrote a sex education pamphlet for her children, as the result of the lack of any existing educational material that met her standards, which included scientific correctness, sex-positivity, and discussion of the emotional side of sexual relationships. The arrest of William Sanger in 1915 for distributing Margaret Sanger's birth control pamphlet catalyzed the birth control movement in the United States, and this time Dennett decided to get involved.