the breaker boys of the pennsylvania coal mines sifted through piles of coal picking out chunks of rock and slate and breaking larger pieces of coal into smaller, more manageable pieces. the breakers were used from the 1860s-1920s, despite public protests due to their age (as young as nine!). many children were injured or killed by falling down chutes, being crushed by coal, or from lung problems. cheers to child labor laws! images via shorpy.