Numerous demographic and economic changes over the past decades have led to complex family systems with diverse and unclearly defined roles for fathers, and have significantly increased research and policy interests in delineating fathers' influence on child well-being. The current research proposes an integrated series of analyses using data from the Three City Study of Welfare, Children and Families, a new multimethod, longitudinal project on predominantly African American and Hispanic children in low-income families in urban neighborhoods. These data provide rich information on both residential and nonresidential fathers, family processes, and child outcomes from a variety of sources, including father, mother and child reports, direct assessments, and observations. The proposed research will inject a developmental and family systems perspective within an economic and sociological theoretical framework that considers the impact of fathers' financial, human, and social capital on children's healthy developmental trajectories. The primary goals of this research are: (1) to delineate the independent effects over time of fathers' financial, human and social capital on preschool children's cognitive skills, prosocial behaviors, and emotional and behavioral problems; (2) to delineate the moderating impact of fathers' residence status, mother-father conflict, and fathers' race/ethnicity; and (3) to address whether fathers' impacts are mediated through the home environment and maternal functioning. Based on previous research and theory, the following hypotheses are developed. (1) Fathers' financial capital will function similarly for residential and nonresidential fathers, will be mediated through the quality of the home environment and maternal stress, and will have a primary impact on children's cognitive outcomes. (2) Fathers' human capital will have a stronger impact on children's cognitive and socio-emotional functioning for residential versus nonresidential fathers and will be mediated by the quality of the home environment. (3) Fathers' social capital will be the most significant predictor of children's cognitive and socio-emotional outcomes, will be moderated by parental conflict, and will be partially mediated through the quality of the home environment and maternal functioning. Multiple regression and structural equation path modeling techniques will be employed.