OBJECTIVES: We sought to assess whether the disparity in mortality rates between Black and White men decreased from the beginning to the end of the 20th century. METHODS: We used Cox proportional hazard models for mortality to estimate differences in longevity between Black and White Civil War veterans from 1900 to 1914 (using data from a pension program) and a later cohort of male participants (using data from the 1992 to 2006 Health and Retirement Study). In sensitivity analysis, we compared relative survival of veterans for alternative baseline years through 1914. RESULTS: In our survival analysis, the Black-White male difference in mortality, both unadjusted and adjusted for other influences, did not decrease from the beginning to the end of the 20th century. A 17% difference in Black-White mortality remained for the later cohort even after we controlled for other influences. Although we could control for fewer other influences on longevity, the Black-White differences in mortality for the earlier cohort was 18%. CONCLUSIONS: In spite of overall improvements in longevity, a major difference in Black-White male mortality persists.