The weekly wage gap between black and white female workers narrowed by 15 percentage points during the 1940s. We employ a semi-parametric technique to decompose changes in the distribution of wages. We find that changes in worker characteristics (such as education, occupation and industry, and region of residence) can account for a significant portion of wage convergence between black and white women, but that changes in the wage structure, including large black-specific gains within regions, occupations, industries, and educational groups, made the largest contributions. The single most important contributing factor to the observed convergence was a sharp increase in the relative wages of service workers (where black workers were heavily concentrated) even as black women moved out of domestic service jobs.