Using a comprehensive database constructed from the pension files of US Civil War veterans, we explore characteristics and occurrence of type 2 diabetes among older black and white males, living circa 1900. We find that rates of diagnosed diabetes were much lower among males in this period than a century later. In contrast to the late 20th Century, the rates of diagnosed diabetes were lower among black than among white males, suggesting that the reverse pattern is of relatively recent origin. Two-thirds of both white and black veterans had body-mass indexes (BMIs) in the currently recommended weight range, a far higher proportion than documented by recent surveys. Longevity among persons with diabetes was not reduced among Civil War veterans, and those with diabetes suffered comparatively few sequelae of the condition. Over 90% of black veterans engaged in low paying, high-physical effort jobs, as compared to about half of white veterans. High rates of work-related physical activity may provide a partial explanation of low rates of diagnosed diabetes among blacks. We found no evidence of discrimination in testing by race, as indicated by rates of examinations in which a urinalysis was performed. This dataset is valuable for providing a national benchmark against which to compare modern diabetes prevalence patterns.