The US Army's 1988 Anthropometric Survey (ANSUR) data set is analysed in order to estimate the secular trend of their physical stature and body mass index while controlling for ethnic composition as well as place of birth of their parents. Separate analysis for blacks and whites stratified by gender is presented. The stature of the American population remained constant during most of the period considered, and no substantial ethnic or spatial effects were found. These results add further support to trends based on the National Health and Nutrition Examination Surveys and imply that the stagnation in height found in those data sets is most probably not biased by the omitted variables pertaining to own ethnicity or second-generation effects of parents' ethnicity or foreign birth.