The process of forming a committed, romantic relationship is described as a developmental phenomenon that cannot be accurately viewed without the context of prior relationship experiences because the social competencies that facilitate successful navigation of the tasks of relationship formation are developed in relationships. Furthermore, a cumulative relationship history that has a negative influence may lead to poor emotional health, further disrupting relationship formation processes through that mechanism. Hypotheses were tested using data from a prospective longitudinal study of participants (218 women, 174 men) who were not in a romantic relationship at initial data collection and reported on their relationship status 4 times over the course of 1 year while completing the READY or RELATionship Evaluation (RELATE). Cumulative relationship history and emotional health prospectively predicted the intercepts in longitudinal growth curve analyses of relationship status, while mediational analyses supported the hypothesis that emotional health partially mediates the influence of cumulative relationship history on relationship status. The findings support the developmental conceptualization that inter- and intrapersonal capacities increase the probability of forming a committed, romantic relationship over time.