Labor unions might have various effects beyond the workplace. We link data on mothers from the National Longitudinal Survey of Youth (NLSY79) to data on their children from the NLSY79 Child Survey to analyze whether a mother’s unionization history while a child is growing up affects two childhood outcomes–cognitive skill and behavior–and two adult outcomes–educational attainment and earnings. We similarly use the Panel Study of Income Dynamics (PSID) to analyze the effect of the unionization history of the household heads on similar childhood and adult outcomes. As these outcomes are likely the product of cumulative childhood experiences, we emphasize the use of unique, cumulative measures of mother or household head union status.