Communities urbanize when the net benefits to urbanization exceed rural areas. Body mass, height, and weight are biological welfare measures that reflect the net difference between calories consumed and calories required for work and to withstand the physical environment. Individuals of African-decent had greater BMIs, heavier weights, and shorter statures. Urban farmers had lower BMIs, shorter statures, and lower weight than rural farmers. Over the late 19th and early 20th centuries, urban and rural BMIs, height, and weight were constant, and rural farmers had greater BMIs, taller statures, and heavier weights than urban farmers and workers in other occupations.

Average stature reflects cumulative net nutrition and health during economic development. This study introduces a difference-in-decompositions approach to show that although 19th century African-American cumulative net nutrition was comparable to working class whites, it was made worse-off with the transition to free-labor. Average stature reflects net nutrition over the life-course, and adult blacks born under bound-labor had greater age related statures loss than blacks under free-labor. Agricultural worker's net nutrition was better than workers in other occupations and was better-off under free-labor and industrialization. Within-group stature variation was greater than across-group variation, and white within-group stature variation associated with socioeconomic status was greater than African-Americans.