(Contributors: Emma Unekis and Nick Vialpando)
Child labor was fairly common in the early 20th century: in 1900, 18 percent of all workers in the United States were under the age of 19. In the decades after the turn of the century, educational reformers managed to convince many native-born parents of the significance of primary education in a child’s life and to establish some basic state laws establishing requirements for school attendance and minimum wage. However, these laws had many loopholes and were loosely enforced, and poorer families often relied on the additional income children brought.
Child labor was perhaps especially common among immigrants, partly because immigrant families were often particularly dependent on the labor of all family members, and partly because many of these immigrant parents were from rural backgrounds and held old beliefs about the benefits of child labor.
In Boulder, only about 1% of the children were recorded as being a part of the workforce in the 1920 census. This small percentage may result from the fact that Boulder was not an industrial city with a large need for factory workers, nor was it a particularly poor area where children needed to work in order to supplement their parents’ low income.
Of the kids who were working in Boulder, most of the jobs held were involved in agriculture or mining. A strong agricultural industry developed in Boulder’s early history in order to support the mining industry. Farming jobs were pretty standard for children in the 1920s; the prevalence of mining jobs came from the history of Boulder. Boulder first attracted settlers because of the promise of mining in the area. Thus, because of the importance to the area and economy, it is not surprising that some children, too, would become a part of the mining industry.
Figure 1. Working children by age group with different immigrant backgrounds (as represented by mother’s country of birth), Boulder County 1920 
The realities of child labor in the mines the early 20th century were harsh. Children were useful in mines because they could fit into small spaces and were easy to control. Faced with back-breaking labor and exhausting shifts, fatigued child workers suffered high accident rates. In some cases, children would work their fingers down to the bone breaking up coal. Those who were injured or maimed in the course of their duties often received no compensation. Also, they were often forced to give up on their education in lieu of this hard work. Two of the main jobs held by children in the mines were “trappers” and “breaker boys”. A child working as a trapper was assigned to sit and open a wooden door which would allow the passage of coal cars. The door would have to be opened anywhere from 12 to 50 times a day and the rest of the time was spent waiting in the darkness. “Breaker boys” used a coal breaker to separate slate and other impurities from the coal before it was shipped. In order to perform this job, the young boys would be positioned on wooden benches above a conveyor belt so that they could remove impurities as the coal came by. These dangerous jobs were no place for children. Children continued to work in mines until the Fair Labor Standards Act of 1938.
 For clarity, the children were grouped into regions of origin rather than countries. The regions contain data from the following countries/areas:
Scandinavia: Sweden, Norway
Western Europe: France, Germany, Switzerland, Netherlands
Eastern Europe: Yugoslavia, Romania, Poland, Czechoslovakia, Hungary, Lithuania
Great Britain and Ireland: England, Scotland, Wales, Ireland
Japan, Mexico, Canada, and Russia are of course self-explanatory.