W hat accounts for differences in job tenure? Turnover and mobility, by providing differential opportunities for advancement and individual attainment, are key mechanisms for understanding occupational segregation, social stratification, and internal labor markets that have long interested sociologists (Baron and Bielby 1980;Jacobs 1989;Osterman 1987;Reskin 1993). Over decades of inquiry, scholars have elucidated several factors that contribute to job durations, including both individual and structural characteristics (Rosenfeld 1992). While the traditional approach to job mobility highlights the match between individuals and jobs at a moment in time, more recent scholars have incorporated temporal dynamics and suggested that evolutionary patterns at the group level (Sørensen 2000) or across the industrial sector (Haveman and Cohen 1994) influence turnover propensities. This dynamic approach begins to highlight how the past impinges on the present. We expand on these insights and further emphasize the role that local histories play in shaping turnover propensities at the level of individual positions. The microlevel structures created when agents first establish organizational positions are important sources of internal constraint.This article considers how local firm histories influence individual turnover rates in organizations. We argue that position imprints-the legacies left by the first incumbents of particular functional positions-constrain subsequent position holders. We show that the functional experience of the person who creates a position influences the turnover rate of successors who later occupy that position. When the first position holder has an atypical background, all successors experience high turnover rates. Individuals who are both typical with respect to the normative environment and similar to the position imprint have the lowest turnover rates. Surprisingly, we find lower turnover rates among individuals who match the position imprint even if they violate normative expectations. Thus, contrary to institutional theory predictions, we find that local firm histories dominate. In revealing how social structures emerge within firms and affect individual outcomes, our research revisits core topics of bureaucratization and organizational stratification including idiosyncratic jobs, occupational segregation, and differential mobility. In addition, we integrate structuralist and interactionist perspectives on role theory by considering how roles are created. Finally, in demonstrating the effects of position imprints on successor mobility we add a temporal dimension to theories of turnover.