Mastery involves a sense of having control over one's surroundings and an ability to accomplish meaningful goals and determine important meaningful outcomes across situations. Mastery is a dynamic, learned resource that has implications for mental health. Although mastery is known to be influenced by exposure to family members (i.e., parental socialization, parenting styles; provided opportunities for autonomy and choice) there remain few long-term considerations of intergenerational transmission of mastery within families and the enduring implications for offspring's mental health and adjustment. Using a nationally representative sample from the National Longitudinal Survey of Youth, the current study addresses the longitudinal effects of mothers' early sense of mastery on adolescent and adult offspring's mastery and well-being. In considering mothers' reports between 1987 and 1992 and offspring's ongoing reports between 1994 and 2012; this study addressed questions about direct, moderated, and mediated mother effects on longitudinal offspring outcomes. Mother mastery and mother self-esteem predicted offspring's respective reports, but only mother mastery predicted offspring depressive symptoms. Effects of mother mastery, but not mother self-esteem, were moderated by offspring age. Older offspring of high mastery mothers showed the largest benefits for reported mastery. Older offspring of low mastery mothers reported the greatest concerns with depressive symptoms. Last, effects of mother mastery on offspring depressive symptoms were mediated by offspring mastery and self-esteem. We discuss the fit of these findings with existing theories and empirical work on intergenerational transmission.