A breaker boy was a coal-mining worker in the United States and United Kingdom whose job was to separate impurities from coal by hand in a coal breaker. Although breaker boys were primarily children, elderly coal miners who could no longer work in the mines because of age, disease, or accident were also sometimes employed as breaker boys. The use of breaker boys began in the mid-1860s. Although public disapproval of the employment of children as breaker boys existed by the mid-1880s, the practice did not end until the 1920s.
Coal came into wide use in late 1590s in the United Kingdom after the island nation was widely deforested and a ban was placed on the harvesting of wood by Charles I of England so that forests could be used solely by the Royal Navy. A newly emergent middle class increasingly demanded glass for windows, and the glass-making industry relied heavily on charcoal for fuel. With charcoal no longer available, this industry turned to coal. Demand for coal also increased after the invention of the reverbatory furnace and the development of methods for casting iron objects such as cannon.
The first function of a coal breaker is to break coal into pieces and sort these pieces into categories of nearly uniform size, a process known as breaking. But coal is often mixed with impurities such as rock, slate, sulphur, ash (or "bone"), clay, or soil. Thus, the second function of a coal breaker is to remove as many impurities as economically desirable and technologically feasible, and then grade the coal based on the percent of impurities remaining. This was not necessary when coal was used in cottage-industry grade production methods, but became necessary when economies of scale moved production into early factories with a larger workforce and those installations began producing glass and iron in greater quantities. These quantities may vary in price.
In the U.S. prior to 1830, very little bituminous coal was mined and the fuel of the early American Industrial Revolution— anthracite coal underwent little processing before being sent to market, which was primarily iron works and smithies producing wrought iron. The miner himself would use a sledgehammer to break up large lumps of coal, then use a rake whose teeth were set two inches apart to collect the larger pieces of coal for shipment to the surface for such were easiest to pack densely in the sack-like bags that could be slung over the back, or onto a pack animal for the trip out of the mine.