I would say that exploitation would be one critical element to help articulate the condition of children during the Industrial Revolution.  The need for progress and demand for material wealth resulted in the abandonment of many childrens' childhood in the very idea that they were made to compete with adults for jobs, causing them to lose out on many of the basic principles and elements that create the foundation for a healthy childhood.  The idea of children working in unsafe and hazardous conditions as well as for long hours, with little compensation helps to create a vision where the notion of "progress" has to be openly questioned and debated.