In the last four decades, the United States has witnessed a retreat from marriage, marked by high rates of nonmarital births and divorce, as well as lower rates of marriage. Although a growing body of research on the retreat from marriage has focused on its social and economic causes, little attention has been paid to the role that cultural institutions play in furthering or resisting matrimony. This paper focuses on the role that religious institutions – and the norms and behaviors they promote – play in encouraging marriage among new parents in urban America. Using longitudinal data from the Fragile Families and Child Wellbeing Study, we find that urban mothers who have a nonmarital birth, especially African American mothers, are significantly more likely to marry within a year of that birth if they attend church frequently. We also find that this religious effect is mediated in part by the relationship-related beliefs and behaviors (e.g., affection between partners). Thus, by fostering beliefs and behaviors that support matrimony, religious institutions help urban mothers make the transition to marriage in communities where marriage has become increasingly infrequent. (Author abstract).