Published in 1912 on the heels of Twenty Years at Hull-House and at the height of Jane Addams's popularity, A New Conscience and an Ancient Evil assesses the vulnerability of the rural and immigrant working-class girls who moved to Chicago and fell prey to the sexual bartering of what was known as the white slave trade.

Addams offers lurid accounts–-drawn from the records of Chicago's Juvenile Protection Association–-of young women coerced into lives of prostitution by men who lurked outside hotels and sweatshops. Because they lacked funds for proper recreation, Addams argues, poor and socially marginalized women were susceptible to sexual slavery, and without radical social change they would perhaps be "almost as free" as young men. In addition to promoting higher wages and better living conditions, Addams suggests that a longer period of public education for young women would deter them from the dangers of city life.

Despite its appeal to middle–class readers eager for tales of sexual excess and the rape of innocence, the press and prominent intellectuals criticized A New Conscience and an Ancient Evil for being disproportionately hysterical to its philosophical weight. Katherine Joslin's introduction considers the controversial reactions to the book and the circumstances of its publication. Behind the sensationalism of the narratives, Joslin locates themes including the commodification of sex and the importance of marriage for young women.
| Cover Title Page Contents Introduction: Slum Angels Preface 1. An Analogy 2. Recent Legal Enactments 3. Amelioration of Economic Conditions 4. Moral Education and Legal Protection of Children 5. Philanthropic Rescue and Prevention 6. Increased Social Control Index