Whites’ wealth advantage compared to blacks and Hispanics is vast and increases with age. While prior research on wealth gaps focuses primarily on wealth levels, we adopt a life-course perspective that treats wealth as a cumulative outcome and examine wealth accumulation across individuals’ lives. We test to what extent intergenerational disadvantage and disparities in achieved characteristics explain accumulation disparities. We hypothesize that disparities in wealth determinants, like income and education, family and household characteristics, and homeownership and local context, increase through early and middle adulthood, widening wealth accumulation gaps. Using the National Longitudinal Survey of Youth 1979, we show that whites accumulate wealth more rapidly than blacks and Hispanics throughout early and middle adulthood, with the result that both groups fall further behind whites in amassed wealth with each passing year. Furthermore, the accumulation gap grows substantially in the 30s, so that blacks and Hispanics in this age range lose ground at an increasing annual rate. We find that adjusting for intergenerational disadvantage reduces the Hispanic-white and black-white gaps in wealth accumulated between ages 20 and 50 by over 40 percent and 50 percent, respectively, and even more in young adulthood. Yet, disparities in outcomes like income, marriage, and homeownership rise with age; together, these intragenerational processes explain a greater share of accumulation gaps in middle adulthood than at younger ages. These findings highlight that wealth gaps in the United States are both shaped by intergenerational legacies of disadvantage and created fresh in each generation through unequal distribution of achieved wealth-enhancing traits.