Retrospective life history data are used in this analysis of the mechanisms which lead to differential levels of occupational success. The paper is based on data collected from a cohort of black men and a cohort of nonblack men, aged 30-39 in 1968. The measure of occupational achievement used throughout is the occupational status of the first job held after last leaving fulltime education and the status of the job held 10 years later. The analysis shows that educational level far outweighs other background characteristics in determining the occupational status of the first job. Partly due to occupational discrimination, the value of education in terms of the status it brings is about twice as great for nonblacks as for blacks. This difference in the effects of education, combined with lower educational attainment by blacks, results in considerably lower status levels. After 10 years, the status of nonblacks showed an increase of 30.8 percent, whereas that of blacks increased 15.9 percent. The study found that roughly half of the difference in status change was due to original levels of resources and the remainder was due to the differential efficacy of these resources. The efficacy of intervening events such as on-the-job training showed no significant differences between blacks and nonblacks. (Author/BH)