Eastern Belgium provides a range of examples of early industrialization. In the nineteenth century, well-established proto-industrial textile and iron production was replaced by mechanization in rapidly growing cities. In this article we examine the consequences of this transition on heights of young men in seven communities with contrasting histories. Men in this area were unusually short in the early nineteenth century, but the trend was strongly upward. There is also some evidence that urban areas experienced setbacks when they were growing most rapidly. Comparison of heights among occupations shows dramatic differences between rich and poor. The gap between the poorest and the wealthiest was at least eight centimeters, and heights seem to reflect even small differences in childhood experience. However, gains in height were larger among the poor, reducing differences within the working class by mid-century.