In this sweeping history of reproductive surgery in Mexico, Elizabeth O'Brien traces the interstices of religion, reproduction, and obstetric racism from the end of the Spanish empire through the post-revolutionary 1930s. Examining medical ideas about operations (including cesarean section, abortion, hysterectomy, and eugenic sterilization), Catholic theology, and notions of modernity and identity, O'Brien argues that present-day claims about fetal personhood are rooted in the use of surgical force against marginalized and racialized women. This history illuminates the theological, patriarchal, and epistemological roots of obstetric violence and racism today.