For over a quarter century anthropometric historians have struggled to identify and measure the numerous factors that affect adult stature, which depends upon diet, disease and physical activity from conception to maturity. I simplify this complex problem by assessing nutritional status in a particular year using synthetic longitudinal data created from measurements of children born in the same year but measured at adjacent ages, which are abundantly available from 28,000 slave manifests housed at the National Archives. I link this evidence with annual measures of economic conditions and new measures of the disease environment to test hypotheses of slave owner behavior. Height-by-age profiles furnish clear evidence that owners substantially managed slave health. The short-term evidence shows that weather affected growth via exposure to pathogens and that owners modified net nutrition in response to sustained price signals.