This paper examines how the fertility of enslaved women was affected by the promise of freedom. Exploiting geographic variation in the effect of the Fugitive Slave Law of 1850, I demonstrate a negative correlation between fertility and the distance to freedom. This negative correlation is stronger on larger plantations but weaker when the slaveholder is a woman. A similar correlation is not present for white children, slave children with white fathers, or slave children born prior to the Fugitive Slave Law. The negative correlation suggests that the promise of freedom played an important role in the everyday lives of slaves.