The Charleston Heart Study and the Evans County Study were both begun in 1960 as prospective cohort studies designed to study risk factors of cardiovascular disease in biracial communities. The Charleston Heart Study cohort comprised a random sample of Black and white men and women residents of Charleston County South Carolina who were 35 years of age or older in 1960 (n=2281). For the Evans County Study (n=3102), 100 percent of the population of Evans County, Georgia who were 40 years and older and 50 percent of the residents 15-39 years of age were recruited (92 percent response rate).