Coronary heart disease is the leading cause of death among United States Blacks, where coronary heart disease mortality rates are among the highest in the world. There has been a marked decline in coronary heart disease mortality among Blacks in the United States including South Carolina since 1968 for reasons not well explained, although hypertension control probably has contributed to the decline. In spite of this decline, evidence emerged that fatal and non-fatal coronary heart disease rates in Blacks exceeds those of whites. Charleston Heart Study data showed that coronary heart disease cumulative survival probabilities for Black men were lower than white men during the first 20 years of the 25 year observation period. A secular trend manifested itself with relatively higher rates in Blacks but in any event, there was evidence that coronary disease was a major threat to Blacks.