Objectives Studies of male and female long bone growth in past populations are limited and usually constrained by the lack of personal identification. This article aimed to evaluate long bone growth in a series of mid‐19th century documented burials associated with the urban poor from Bethnal Green, London, UK. Materials and methods Maximum diaphyseal lengths from 74 males and 70 females (2 months to 12 years) were compared to modern reference data from North America. Diaphyseal lengths were expressed as a percentage of expected length and an average percentage value was calculated across all available long bones. An index of growth progression was introduced to explore differences in the progress of males and females towards their projected adult size. Results Deviation from the expected growth attainment was evident in both sexes in the archaeological series by 2–4 months of age. Only 19.4% (28/144) of the children had attained an average long bone length >90% of the predicted mean in the reference series. The percentage of expected growth attainment decreased steadily in both sexes during infancy and early childhood. Overall, females deviated further from their expected growth progression than males. Discussion Growth faltering in both males and females was established during infancy (<1 year) with no evidence for recovery in older age groups. Early weaning and inadequate artificial feeding, together with impoverished living conditions and limited sanitary provision, most likely impacted on childhood growth.