Growth-attained curves have shown only limited effectiveness in studies of long bone growth in archaeological populations. As an alternative, the length of long bone diaphyses in children aged 0 to 12 years from the Libben skeletal collection were first normalized by average adult long bone length, and derivatives of fitted curves were then used to determine age-specific growth velocity. The sample was compared to healthy Euroamerican children from Denver, Colorado (Maresh: American Journal of Diseases of Children 89:725–742, 1955). Results indicate almost identical patterns of growth in the two populations with one exception: the Libben sample shows significantly diminished velocity during the first three years of life. This period of depressed growth coincides with high levels of infectious disease.