The authors discuss changes in U.S. morbidity and mortality in the early twentieth century with a focus on data from the Union Army recruit sample. sample consists of approximately 36000 men born between 1820 and 1843.... This paper examines the work of five scholars who have been among those principally involved over the past six years not only in the construction of the data set but in using the Union Army data to examine an interesting range of problems associated with aging. (EXCERPT)