The purpose of this study was to explore factors that may help explain the mortality differences between African Americans and Whites. This study was a retrospective analysis of data from Tennessee’s 95 counties. Standardized mortality ratios (SMRs) for African Americans were determined based on White, all-cause, age-specific mortality rates, and served as the dependent variable. Potential explanatory variables included measures of demography, socioeconomic status, and social environment. Bivariate and multivariate analyses showed a significant association between SMR and population density (t=2.18, p=.037) among 36 counties, with more than 20 African American deaths per year, and between SMR and the proportion of the population that is African American (t=2.23, p=.033) in an analysis that included all 95 counties. Mortality differences based on demographic characteristics, rather than on the usual social determinants of health, raise further questions about the root causes of health inequities.